Methods of regenerating aromatization catalysts

ABSTRACT

Methods for treating or rejuvenating a spent catalyst are described. These methods can employ a step of halogenating the spent catalyst, followed by decoking the halogenated spent catalyst. The halogenation step can utilize fluorine and chlorine together, or fluorine and chlorine can be applied sequentially.

REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 13/412,399, filed on Mar. 5, 2012, now U.S. Pat.No. 8,716,161, which is incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

The catalytic conversion of non-aromatic hydrocarbons into aromaticcompounds, often referred to as aromatization or reforming, is animportant industrial process that can be used to produce benzene,toluene, xylene, and the like. The aromatization or reforming processoften is conducted in a reactor system that can contain one or morereactors containing transition metal based catalysts. These catalystscan increase the selectivity to and/or the yield of the desired aromaticcompounds. However, under commercial reaction conditions, thesecatalysts slowly lose their activity, often indicated by a loss ofselectivity to desired aromatic compounds and/or a reduction inconversion rates. Such catalysts are often referred to as “spent”catalysts once economic or operational thresholds are passed.

Because of their commercial importance and the expense incurred inproducing fresh catalyst to replace spent catalyst, there is an ongoingneed for improved methods of restoring catalytic activity to spentaromatization catalysts. Accordingly, it is to this end that the presentdisclosure is directed.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify required oressential features of the claimed subject matter. Nor is this summaryintended to be used to limit the scope of the claimed subject matter.

Methods for treating or regenerating spent catalysts comprising atransition metal and a catalyst support are disclosed and describedherein. One such method of treating or regenerating a spent catalyst cancomprise (i) contacting the spent catalyst with a halogen-containingstream comprising chlorine and fluorine to produce a halogenated spentcatalyst; and (ii) contacting the halogenated spent catalyst with adecoking gas stream comprising oxygen.

Another method of treating or regenerating a spent catalyst can comprise(1) contacting the spent catalyst with a fluorine-containing streamcomprising a fluorine-containing compound to produce a fluorinated spentcatalyst; (2) contacting the fluorinated spent catalyst with achlorine-containing stream comprising a chlorine-containing compound toproduce a fluorinated-chlorinated spent catalyst; and (3) contacting thefluorinated-chlorinated spent catalyst with a decoking gas streamcomprising oxygen.

Yet another method of treating or regenerating a spent catalyst cancomprise (1) contacting the spent catalyst with a chlorine-containingstream comprising a chlorine-containing compound to produce achlorinated spent catalyst; (2) contacting the chlorinated spentcatalyst with a fluorine-containing stream comprising afluorine-containing compound to produce a chlorinated-fluorinated spentcatalyst; and (3) contacting the chlorinated-fluorinated spent catalystwith a decoking gas stream comprising oxygen.

Also disclosed herein are various processes for reforming hydrocarbons.One such reforming process can comprise (a) contacting a hydrocarbonfeed with an aromatization catalyst comprising a transition metal and acatalyst support under reforming conditions in a reactor system toproduce an aromatic product; (b) performing step (a) for a time periodsufficient to form a spent aromatization catalyst; (c) contacting thespent aromatization catalyst with a halogen-containing stream comprisingchlorine and fluorine to produce a halogenated spent catalyst; and (d)contacting the halogenated spent catalyst with a decoking gas streamcomprising oxygen.

Another process for reforming hydrocarbons can comprise (A) contacting ahydrocarbon feed with an aromatization catalyst comprising a transitionmetal and a catalyst support under reforming conditions in a reactorsystem to produce an aromatic product; (B) performing step (A) for atime period sufficient to form a spent aromatization catalyst; (C)contacting the spent aromatization catalyst with a fluorine-containingstream comprising a fluorine-containing compound to produce afluorinated spent catalyst; (D) contacting the fluorinated spentcatalyst with a chlorine-containing stream comprising achlorine-containing compound to produce a fluorinated-chlorinated spentcatalyst; and (E) contacting the fluorinated-chlorinated spent catalystwith a decoking gas stream comprising oxygen.

Yet another process for reforming hydrocarbons can comprise (A)contacting a hydrocarbon feed with an aromatization catalyst comprisinga transition metal and a catalyst support under reforming conditions ina reactor system to produce an aromatic product; (B) performing step (A)for a time period sufficient to form a spent aromatization catalyst; (C)contacting the spent aromatization catalyst with a chlorine-containingstream comprising a chlorine-containing compound to produce achlorinated spent catalyst; (D) contacting the chlorinated spentcatalyst with a fluorine-containing stream comprising afluorine-containing compound to produce a chlorinated-fluorinated spentcatalyst; and (E) contacting the chlorinated-fluorinated spent catalystwith a decoking gas stream comprising oxygen.

Both the foregoing summary and the following detailed descriptionprovide examples and are explanatory only. Accordingly, the foregoingsummary and the following detailed description should not be consideredto be restrictive. Further, features or variations may be provided inaddition to those set forth herein. For example, certain embodiments maybe directed to various feature combinations and sub-combinationsdescribed in the detailed description.

DEFINITIONS

To define more clearly the terms used herein, the following definitionsare provided. Unless otherwise indicated, the following definitions areapplicable to this disclosure. If a term is used in this disclosure butis not specifically defined herein, the definition from the IUPACCompendium of Chemical Terminology, 2^(nd) Ed (1997), can be applied, aslong as that definition does not conflict with any other disclosure ordefinition applied herein, or render indefinite or non-enabled any claimto which that definition is applied. To the extent that any definitionor usage provided by any document incorporated herein by referenceconflicts with the definition or usage provided herein, the definitionor usage provided herein controls.

Regarding claim transitional terms or phrases, the transitional term“comprising,” which is synonymous with “including,” “containing,”“having,” or “characterized by,” is inclusive or open-ended and does notexclude additional, unrecited elements or method steps. The transitionalphrase “consisting of” excludes any element, step, or ingredient notspecified in the claim. The transitional phrase “consisting essentiallyof” limits the scope of a claim to the specified materials or steps andthose that do not materially affect the basic and novelcharacteristic(s) of the claim. A “consisting essentially of” claimoccupies a middle ground between closed claims that are written in a“consisting of” format and fully open claims that are drafted in a“comprising” format. For example, absent an indication to the contrary,describing a compound or composition as “consisting essentially of” isnot to be construed as “comprising,” but is intended to describe therecited component that includes materials which do not significantlyalter the composition or method to which the term is applied. Forexample, a feedstock consisting essentially of a material A can includeimpurities typically present in a commercially produced or commerciallyavailable sample of the recited compound or composition. When a claimincludes different features and/or feature classes (for example, amethod step, feedstock features, and/or product features, among otherpossibilities), the transitional terms comprising, consistingessentially of, and consisting of apply only to the feature class towhich it is utilized, and it is possible to have different transitionalterms or phrases utilized with different features within a claim. Forexample, a method can comprise several recited steps (and othernon-recited steps), but utilize a catalyst system consisting of specificcomponents; alternatively, consisting essentially of specificcomponents; or alternatively, comprising the specific components andother non-recited components.

In this disclosure, while compositions and methods are often describedin terms of “comprising” various components or steps, the compositionsand methods can also “consist essentially of” or “consist of” thevarious components or steps, unless stated otherwise.

The terms “a,” “an,” and “the” are intended to include pluralalternatives, e.g., at least one. For instance, the disclosure of “atransition metal,” “a halogen-containing compound,” etc., is meant toencompass one, or mixtures or combinations of more than one, transitionmetal, halogen-containing compound, etc., unless otherwise specified.

A “spent” catalyst is used herein generally to describe a catalyst thathas unacceptable performance in one or more of catalyst activity,hydrocarbon feed conversion, yield to a desired product(s), selectivityto a desired product(s), or an operating parameter, such asoutput/production rate or reforming temperature, although thedetermination that a catalyst is “spent” is not limited only to thesefeatures. In some embodiments, the fresh catalyst can have an activityX, the spent catalyst can have an activity Z, and the treated orrejuvenated catalyst can have an activity Y, such that Z<Y<X. In certainembodiments disclosed herein, the rejuvenated catalyst often can have anactivity that is from about 50% to about 80% of the activity of thefresh catalyst (e.g., Y=about 0.5X to about 0.8X). Such catalystactivity comparisons are meant to use the same production run (batch) ofcatalyst, tested on the same equipment, and under the same test methodand conditions.

For any particular compound or group disclosed herein, any name orstructure (general or specific) presented is intended to encompass allconformational isomers, regioisomers, stereoisomers, and mixturesthereof that can arise from a particular set of substituents, unlessotherwise specified. The name or structure (general or specific) alsoencompasses all enantiomers, diastereomers, and other optical isomers(if there are any) whether in enantiomeric or racemic forms, as well asmixtures of stereoisomers, as would be recognized by a skilled artisan,unless otherwise specified. For example, a general reference to pentane,for example, includes n-pentane, 2-methyl-butane, and2,2-dimethylpropane; and a general reference to a butyl group includes an-butyl group, a sec-butyl group, an iso-butyl group, and a t-butylgroup.

In one embodiment, a chemical “group” can be defined or describedaccording to how that group is formally derived from a reference or“parent” compound, for example, by the number of hydrogen atoms removedfrom the parent compound to generate the group, even if that group isnot literally synthesized in such a manner. These groups can be utilizedas substituents or coordinated or bonded to metal atoms. By way ofexample, an “alkyl group” formally can be derived by removing onehydrogen atom from an alkane. The disclosure that a substituent, ligand,or other chemical moiety can constitute a particular “group” impliesthat the well-known rules of chemical structure and bonding are followedwhen that group is employed as described. When describing a group asbeing “derived by,” “derived from,” “formed by,” or “formed from,” suchterms are used in a formal sense and are not intended to reflect anyspecific synthetic methods or procedures, unless specified otherwise orthe context requires otherwise.

Various numerical ranges are disclosed herein. When Applicants discloseor claim a range of any type, Applicants' intent is to disclose or claimindividually each possible number that such a range could reasonablyencompass, including end points of the range as well as any sub-rangesand combinations of sub-ranges encompassed therein, unless otherwisespecified. As a representative example, Applicants disclose that themethods provided herein can employ a halogen-containing streamcontaining Cl and F at a molar ratio of Cl:F in a range from about 0.1:1to about 20:1 in certain embodiments. By a disclosure that the molarratio of Cl:F in the halogen-containing stream can be in a range fromabout 0.1:1 to about 20:1, Applicants intend to recite that the molarratio can be about 0.1:1, about 0.2:1, about 0.3:1, about 0.4:1, about0.5:1, about 0.6:1, about 0.7:1, about 0.8:1, about 0.9:1, about 1:1,about 2:1, about 3:1, about 4:1, about 5:1, about 6:1, about 7:1, about8:1, about 9:1, about 10:1, about 11:1, about 12:1, about 13:1, about14:1, about 15:1, about 16:1, about 17:1, about 18:1, about 19:1, orabout 20:1. Additionally, the molar ratio of Cl:F can be within anyrange from about 0.1:1 to about 20:1 (for example, the molar ratio canbe in a range from about 0.2:1 to about 10:1), and this also includesany combination of ranges between about 0.1:1 and about 20:1. Likewise,all other ranges disclosed herein should be interpreted in a mannersimilar to this example.

Applicants reserve the right to proviso out or exclude any individualmembers of any such group, including any sub-ranges or combinations ofsub-ranges within the group, that can be claimed according to a range orin any similar manner, if for any reason Applicants choose to claim lessthan the full measure of the disclosure, for example, to account for areference that Applicants may be unaware of at the time of the filing ofthe application. Further, Applicants reserve the right to proviso out orexclude any individual substituents, analogs, compounds, ligands,structures, or groups thereof, or any members of a claimed group, if forany reason Applicants choose to claim less than the full measure of thedisclosure, for example, to account for a reference that Applicants maybe unaware of at the time of the filing of the application.

The term “substituted” when used to describe a group, for example, whenreferring to a substituted analog of a particular group, is intended todescribe any non-hydrogen moiety that formally replaces a hydrogen atomin that group, and is intended to be non-limiting. A group or groups canalso be referred to herein as “unsubstituted” or by equivalent termssuch as “non-substituted,” which refers to the original group in which anon-hydrogen moiety does not replace a hydrogen atom within that group.Unless otherwise specified, “substituted” is intended to be non-limitingand include inorganic substituents or organic substituents as understoodby one of ordinary skill in the art.

As used herein, the term “hydrocarbon” refers to a compound containingonly carbon and hydrogen atoms. Other identifiers can be utilized toindicate the presence of particular groups, if any, in the hydrocarbon(e.g., halogenated hydrocarbon indicates that the presence of one ormore halogen atoms replacing an equivalent number of hydrogen atoms inthe hydrocarbon).

An “aromatic” compound is a compound containing a cyclically conjugateddouble bond system that follows the Hückel (4n+2) rule and contains(4n+2) pi-electrons, where n is an integer from 1 to 5. Aromaticcompounds include “arenes” (hydrocarbon aromatic compounds, e.g.,benzene, toluene, xylene, etc.) and “heteroarenes” (heteroaromaticcompounds formally derived from arenes by replacement of one or moremethine (—C═) carbon atoms of the cyclically conjugated double bondsystem with a trivalent or divalent heteroatoms, in such a way as tomaintain the continuous pi-electron system characteristic of an aromaticsystem and a number of out-of-plane pi-electrons corresponding to theHückel rule (4n+2)). As disclosed herein, the term “substituted” can beused to describe an aromatic group, arene, or heteroarene, wherein anon-hydrogen moiety formally replaces a hydrogen atom in the compound,and is intended to be non-limiting, unless specified otherwise.

As used herein, the term “alkane” refers to a saturated hydrocarboncompound. Other identifiers can be utilized to indicate the presence ofparticular groups, if any, in the alkane (e.g., halogenated alkaneindicates that the presence of one or more halogen atoms replacing anequivalent number of hydrogen atoms in the alkane). The term “alkylgroup” is used herein in accordance with the definition specified byIUPAC: a univalent group formed by removing a hydrogen atom from analkane. The alkane or alkyl group can be linear or branched unlessotherwise specified.

A “cycloalkane” is a saturated cyclic hydrocarbon, with or without sidechains, for example, cyclobutane, cyclopentane, cyclohexane, methylcyclopentane, methyl cyclohexane, etc. Other identifiers can be utilizedto indicate the presence of particular groups, if any, in thecycloalkane (e.g., halogenated cycloalkane indicates that the presenceof one or more halogen atoms replacing an equivalent number of hydrogenatoms in the cycloalkane).

The term “halogen” has its usual meaning. Examples of halogens includefluorine, chlorine, bromine, and iodine.

Although any methods and materials similar or equivalent to thosedescribed herein can be used in the practice or testing of theinvention, the typical methods and materials are herein described.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention. The publications discussed throughout the text are providedsolely for their disclosure prior to the filing date of the presentapplication. Nothing herein is to be construed as an admission that theinventors are not entitled to antedate such disclosure by virtue ofprior invention.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein are methods for treating or regenerating a spentcatalyst, such as a spent aromatization catalyst. Related reformingprocesses also are disclosed.

Methods for Treating Spent Catalysts

Various methods for treating or regenerating spent catalysts comprisinga transition metal and a catalyst support are disclosed and described.One such method of treating or regenerating a spent catalyst cancomprise (or consist essentially of, or consist of):

(i) contacting the spent catalyst with a halogen-containing streamcomprising chlorine and fluorine to produce a halogenated spentcatalyst; and

(ii) contacting the halogenated spent catalyst with a decoking gasstream comprising oxygen.

Generally, the features of any of the methods disclosed herein (e.g.,the spent catalyst, the transition metal, the catalyst support, thehalogen-containing stream, the conditions under which the halogenationstep is conducted, the decoking gas stream, the conditions under whichthe decoking step is conducted, among others) are independentlydescribed herein, and these features can be combined in any combinationto further describe the disclosed methods. Moreover, other process stepscan be conducted before, during, and/or after any of the steps listed inthe disclosed methods, unless stated otherwise. Additionally,reactivated catalysts produced in accordance with the disclosedmethods/processes are within the scope of this disclosure and areencompassed herein.

Step (i) of the method often can be referred to as the halogenationstep, and in the halogenation step, a halogen-containing streamcomprising chlorine (Cl) and fluorine (F) can be contacted with thespent catalyst. In some embodiments, the molar ratio of Cl:F in thehalogen-containing stream can be in a range from about 0.1:1 to about25:1, while in other embodiments, the molar ratio of Cl:F in thehalogen-containing stream can be in a range from about 0.1:1 to about20:1. Molar ratios of Cl:F in the halogen-containing stream in a rangefrom about 0.1:1 to about 15:1, from about 0.2:1 to about 15:1, fromabout 0.2:1 to about 10:1, from about 0.2:1 to about 5:1, from about0.3:1 to about 3:1, from about 0.1:1 to about 1:1, or from about 0.3:1to about 0.8:1, also can be employed in embodiments contemplated herein.

Any compositional attributes of the halogen-containing stream are meantto refer to the incoming halogen-containing stream, prior to contactingthe spent catalyst, unless expressly stated otherwise. As one of skillin the art would readily recognize, the outgoing halogen-containingstream, after contacting the spent catalyst, can vary significantly incomposition from the incoming halogen-containing stream.

The sources of chlorine and fluorine in the halogen-containing streamcan be varied. For instance, the halogen-containing stream can comprisea chlorine-containing compound and a fluorine-containing compound (e.g.,at least two distinct compounds); or a chlorine/fluorine-containingcompound (e.g., at least one compound containing both chlorine andfluorine, or a chlorofluorocarbon); or a chlorine-containing compoundand a chlorine/fluorine-containing compound; or achlorine/fluorine-containing compound and a fluorine-containingcompound; and so forth.

In an embodiment, suitable chlorine-containing compounds can include,but are not limited to, hydrochloric acid, chlorine gas (Cl₂), carbontetrachloride, tetrachloroethylene, chlorobenzene, methyl chloride,methylene chloride, chloroform, allyl chloride, trichloroethylene, achloramine, a chlorine oxide, a chlorine acid, chlorine dioxide,dichlorine monoxide, dichlorine heptoxide, chloric acid, perchloricacid, ammonium chloride, tetramethylammonium chloride,tetraethylammonium chloride, tetrapropylammonium chloride,tetrabutylammonium chloride, methyltriethylammonium chloride, and thelike, or any combination thereof. Other suitable chlorine-containingcompounds can include arenes and alkyl-substituted arenes (e.g.,benzene, toluene, xylene, etc.), where at least one hydrogen atom isreplaced with a Cl atom.

In another embodiment, the chlorine-containing compound can comprise (orconsist essentially of, or consist of) hydrochloric acid; alternatively,chlorine gas (Cl₂); alternatively, carbon tetrachloride; alternatively,tetrachloroethylene; alternatively, chlorobenzene; alternatively, methylchloride; alternatively, methylene chloride; alternatively, chloroform;alternatively, allyl chloride; alternatively, trichloroethylene;alternatively, a chloramine; alternatively, a chlorine oxide;alternatively, a chlorine acid; alternatively, chlorine dioxide;alternatively, dichlorine monoxide; alternatively, dichlorine heptoxide;alternatively, chloric acid; alternatively, perchloric acid;alternatively, ammonium chloride; alternatively, tetramethylammoniumchloride; alternatively, tetraethylammonium chloride; alternatively,tetrapropylammonium chloride; alternatively, tetrabutylammoniumchloride; or alternatively, methyltriethylammonium chloride.

In an embodiment, suitable fluorine-containing compounds can include,but are not limited to, hydrofluoric acid, fluorine gas (F₂),2,2,2-trifluoroethanol, tetrafluoroethylene, carbon tetrafluoride,carbon trifluoride, fluoromethane, heptafluoropropane, decafluorobutane,hexafluoroisopropanol, tetrafluoropropanol, pentafluoropropanol,hexafluorophenylpropanol, perfluorobutyl alcohol, hexafluor-2-propanol,pentafluoro-1-propanol, tetrafluoro-1-propanol,1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol,ammonium fluoride, tetramethylammonium fluoride, tetraethylammoniumfluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride,methyltriethylammonium fluoride, and the like, or any combinationthereof. Other suitable fluorine-containing compounds can include arenesand alkyl-substituted arenes (e.g., benzene, toluene, xylene, etc.),where at least one hydrogen atom is replaced with a F atom.

In another embodiment, the fluorine-containing compound can comprise (orconsist essentially of, or consist of) hydrofluoric acid; alternatively,fluorine gas (F₂); alternatively, 2,2,2-trifluoroethanol; alternatively,tetrafluoroethylene; alternatively, carbon tetrafluoride; alternatively,carbon trifluoride; alternatively, fluoromethane; alternatively,heptafluoropropane; alternatively, decafluorobutane; alternatively,hexafluoroisopropanol; alternatively, tetrafluoropropanol;alternatively, pentafluoropropanol; alternatively,hexafluorophenylpropanol; alternatively, perfluorobutyl alcohol;alternatively, hexafluor-2-propanol; alternatively,pentafluoro-1-propanol; alternatively, tetrafluoro-1-propanol;alternatively, 1,1,1,3,3,3-hexafluoro-2-propanol; alternatively,2,2,3,3,3-pentafluoro-1-propanol; alternatively, ammonium fluoride;alternatively, tetramethylammonium fluoride; alternatively,tetraethylammonium fluoride; alternatively, tetrapropylammoniumfluoride; alternatively, tetrabutylammonium fluoride; or alternatively,methyltriethylammonium fluoride.

Suitable chlorine/fluorine-containing compounds (or chlorofluorocarbons)can include, but are not limited to, CF₃Cl, CF₂Cl₂, CFCl₃, CHFCl₂,CHF₂Cl, C₂F₂Cl₄, C₂F₄Cl₂, and the like, or any combination thereof.Thus, the halogen-containing stream can comprise (or consist essentiallyof, or consist of) a chlorine/fluorine-containing compound orchlorofluorocarbon in certain embodiments.

In addition to chlorine and fluorine, the halogen-containing stream canfurther comprise an inert gas, such as helium, neon, argon, or nitrogen,or combinations of two or more of these materials. In certainembodiments, the halogen-containing stream can comprise (or consistessentially of, or consist of) chlorine, fluorine, and an inert gas, andthe inert gas can be or can comprise nitrogen. In a further embodiment,the halogen-containing stream can comprise (or consist essentially of,or consist of) chlorine gas (Cl₂), fluorine gas (F₂), and nitrogen.

In certain embodiments, the amount of chlorine (Cl) and fluorine (F),individually, in the halogen-containing stream can be less than about 5%by volume. For instance, the halogen-containing stream can comprise aconcentration in ppmv (ppm by volume) of Cl of less than about 25,000and/or a ppmv of F of less than about 25,000; alternatively, a ppmv ofCl of less than about 10,000 and/or a ppmv of F of less than about10,000; alternatively, a ppmv of Cl of less than about 5,000 and/or appmv of F of less than about 5,000; alternatively, a ppmv of Cl of lessthan about 2,500 and/or a ppmv of F of less than about 2,500. Suitableranges of the concentration of Cl and/or F can include, but are notlimited to, the following ranges: from about 50 to about 25,000 ppmv,from about 50 to about 5,000 ppmv, from about 50 to about 2,500 ppmv,from about 50 to about 1,000 ppmv, from about 250 to about 25,000 ppmv,from about 250 to about 10,000 ppmv, from about 250 to about 5,000 ppmv,from about 250 to about 2,000 ppmv, from about 500 to about 5,000 ppmv,from about 500 to about 2,500 ppmv, and the like.

Additionally, or alternatively, the halogen-containing stream can besubstantially free of oxygen-containing compounds, such as oxygen (O₂),water (H₂O), etc. As used herein, “substantially free” ofoxygen-containing compounds means less than 100 ppmw (ppm by weight) ofoxygen-containing compounds in the halogen-containing stream. Therefore,it is contemplated that the amount of oxygen-containing compounds in thehalogen-containing stream can be less than 50 ppmw, less than 25 ppmw,less than 10 ppmw, less than 5 ppmw, or less than 3 ppmw, in certainembodiments. In other embodiments, the amount of oxygen-containingcompounds in the halogen-containing stream can be in range from about0.1 to 100 ppmw, from about 0.5 to 100 ppmw, from about 1 to 100 ppmw,from about 0.1 to about 50 ppmw, from about 0.1 to about 25 ppmw, fromabout 0.1 to about 10 ppmw, or from about 0.1 to about 5 ppmw. While notwishing to be bound by theory, Applicants believe that it can bebeneficial to have substantially no oxygen added during the halogenationstep of the method of treating a spent catalyst.

The halogenation step can be conducted at a variety of temperatures andtime periods. For instance, the halogenation step can be conducted at ahalogenation temperature in a range from about 0° C. to about 500° C.;alternatively, from about 100° C. to about 500° C.; alternatively, fromabout 0° C. to about 400° C.; alternatively, from about 100° C. to about450° C.; alternatively, from about 150° C. to about 350° C.;alternatively, from about 20° C. to about 350° C.; alternatively, fromabout 25° C. to about 300° C.; alternatively, from about 25° C. to about250° C.; alternatively, from about 50° C. to about 280° C.;alternatively, from about 120° C. to about 320° C.; alternatively, fromabout 150° C. to about 300° C.; alternatively, from about 150° C. toabout 280° C.; or alternatively, from about 170° C. to about 250° C. Inthese and other embodiments, these temperature ranges also are meant toencompass circumstances where the halogenation step is conducted at aseries of different temperatures, instead of at a single fixedtemperature, falling within the respective ranges.

The duration of the halogenation step is not limited to any particularperiod of time. Hence, the halogenation step can be conducted, forexample, in a time period ranging from as little as 30-45 minutes to aslong as 12-24 hours, 36-48 hours, or more. The appropriate halogenationtime can depend upon, for example, the halogenation temperature, and theamounts of chlorine and fluorine in the halogen-containing stream, amongother variables. Generally, however, the halogenation step can beconducted in a time period that can be in a range from about 45 minutesto about 48 hours, such as, for example, from about 1 hour to about 48hours, from about 45 minutes to about 24 hours, from about 45 minutes toabout 18 hours, from about 1 hour to about 12 hours, from about 2 hoursto about 12 hours, from about 4 hours to about 10 hours, or from about 2hours to about 8 hours.

Other methods for treating or regenerating spent catalysts comprising atransition metal and a catalyst support also are disclosed and describedherein. In one embodiment, the method of treating or regenerating aspent catalyst can comprise (or consist essentially of, or consist of):

(1) contacting the spent catalyst with a fluorine-containing streamcomprising a fluorine-containing compound to produce a fluorinated spentcatalyst;

(2) contacting the fluorinated spent catalyst with a chlorine-containingstream comprising a chlorine-containing compound to produce afluorinated-chlorinated spent catalyst; and

(3) contacting the fluorinated-chlorinated spent catalyst with adecoking gas stream comprising oxygen.

In another embodiment, the method of treating or regenerating a spentcatalyst can comprise (or consist essentially of, or consist of):

(1) contacting the spent catalyst with a chlorine-containing streamcomprising a chlorine-containing compound to produce a chlorinated spentcatalyst;

(2) contacting the chlorinated spent catalyst with a fluorine-containingstream comprising a fluorine-containing compound to produce achlorinated-fluorinated spent catalyst; and

(3) contacting the chlorinated-fluorinated spent catalyst with adecoking gas stream comprising oxygen.

Generally, the features of any of the methods disclosed herein (e.g.,the spent catalyst, the transition metal, the catalyst support, thefluorine-containing stream, the chlorine-containing stream, theconditions under which the fluorination step is conducted, theconditions under which the chlorination step is conducted, the decokinggas stream, the conditions under which the decoking step is conducted,among others) are independently described herein, and these features canbe combined in any combination to further describe the disclosedmethods. Moreover, other process steps can be conducted before, during,and/or after any of the steps listed in the disclosed methods, unlessstated otherwise. Additionally, reactivated catalysts produced inaccordance with the disclosed methods/processes are within the scope ofthis disclosure and are encompassed herein.

The steps of these methods that utilize a fluorine-containing streamoften can be referred to as fluorination steps, while the steps of thesemethods that utilize a chlorine-containing stream often can be referredto as chlorination steps. Any compositional attributes of thefluorine-containing stream and the chlorine-containing stream are meantto refer to the respective incoming fluorine-containing stream andchlorine-containing stream, prior to contacting the spent catalyst,unless expressly stated otherwise. As one of skill in the art wouldreadily recognize, the outgoing fluorine-containing stream andchlorine-containing stream, after contacting the spent catalyst, canvary significantly in composition from the respective incomingfluorine-containing stream and chlorine-containing stream.

The fluorine-containing compound in the fluorine-containing stream canbe any fluorine-containing compound disclosed herein as being suitableas a fluorine-containing compound in the halogen-containing stream. Forinstance, the fluorine-containing compound can comprise (or consistessentially of, or consist of) fluorine gas (F₂). In addition tofluorine, the fluorine-containing stream can further comprise an inertgas, such as helium, neon, argon, or nitrogen, or combinations of two ormore of these materials. In certain embodiments, the fluorine-containingstream can comprise (or consist essentially of, or consist of) afluorine-containing compound and an inert gas, and the inert gas can beor can comprise nitrogen. In a further embodiment, thefluorine-containing stream can comprise (or consist essentially of, orconsist of) fluorine gas (F₂) and nitrogen.

In certain embodiments, the amount of fluorine (F) in thefluorine-containing stream can be less than about 5% by volume. Forinstance, the fluorine-containing stream can comprise a concentration inppmv (ppm by volume) of F of less than about 25,000; alternatively, appmv of F of less than about 10,000; alternatively, a ppmv of F of lessthan about 5,000; alternatively, a ppmv of F of less than about 2,500.Suitable ranges of the concentration of F can include, but are notlimited to, the following ranges: from about 50 to about 25,000 ppmv,from about 50 to about 5,000 ppmv, from about 50 to about 2,500 ppmv,from about 50 to about 1,000 ppmv, from about 250 to about 25,000 ppmv,from about 250 to about 10,000 ppmv, from about 250 to about 5,000 ppmv,from about 250 to about 2,000 ppmv, from about 500 to about 5,000 ppmv,from about 500 to about 2,500 ppmv, and the like.

The fluorine-containing stream can be substantially free ofoxygen-containing compounds (e.g., oxygen (O₂), water (H₂O), etc.),i.e., can contain less than 100 ppmw (ppm by weight) ofoxygen-containing compounds. Therefore, it is contemplated that theamount of oxygen-containing compounds in the fluorine-containing streamcan be less than 50 ppmw, less than 25 ppmw, less than 10 ppmw, lessthan 5 ppmw, or less than 3 ppmw, in certain embodiments. In otherembodiments, the amount of oxygen-containing compounds in thefluorine-containing stream can be in range from about 0.1 to 100 ppmw,from about 0.5 to 100 ppmw, from about 1 to 100 ppmw, from about 0.1 toabout 50 ppmw, from about 0.1 to about 25 ppmw, from about 0.1 to about10 ppmw, or from about 0.1 to about 5 ppmw. While not wishing to bebound by theory, Applicants believe that it can be beneficial to havesubstantially no oxygen added during the fluorination step of the methodof treating a spent catalyst. Moreover, although not required, thefluorine-containing stream can be substantially free ofchlorine-containing compounds, i.e., can contain less than 100 ppmw (ppmby weight) of chlorine-containing compounds. As above, it iscontemplated that the amount of chlorine-containing compounds in thefluorine-containing stream can be, for instance, less than 50 ppmw, lessthan 10 ppmw, in a range from about 0.1 to 100 ppmw, in a range fromabout 0.1 to about 50 ppmw, or in a range from about 0.1 to about 10ppmw, and the like.

The fluorination step can be conducted at a variety of temperatures andtime periods. For instance, the fluorination step can be conducted at afluorination temperature in a range from about 0° C. to about 500° C.;alternatively, from about 100° C. to about 500° C.; alternatively, fromabout 0° C. to about 400° C.; alternatively, from about 100° C. to about450° C.; alternatively, from about 150° C. to about 350° C.;alternatively, from about 20° C. to about 350° C.; alternatively, fromabout 25° C. to about 300° C.; alternatively, from about 25° C. to about250° C.; alternatively, from about 10° C. to about 100° C.;alternatively, from about 20° C. to about 50° C.; alternatively, fromabout 50° C. to about 280° C.; alternatively, from about 120° C. toabout 320° C.; alternatively, from about 150° C. to about 300° C.;alternatively, from about 150° C. to about 280° C.; or alternatively,from about 170° C. to about 250° C. In these and other embodiments,these temperature ranges also are meant to encompass circumstances wherethe fluorination step is conducted at a series of differenttemperatures, instead of at a single fixed temperature, falling withinthe respective ranges.

The duration of the fluorination step is not limited to any particularperiod of time. Hence, the fluorination step can be conducted, forexample, in a time period ranging from as little as 30-45 minutes to aslong as 12-24 hours, 36-48 hours, or more. The appropriate fluorinationtime can depend upon, for example, the fluorination temperature, and theamount of fluorine in the fluorine-containing stream, among othervariables. Generally, however, the fluorination step can be conducted ina time period that can be in a range from about 45 minutes to about 48hours, such as, for example, from about 1 hour to about 48 hours, fromabout 45 minutes to about 24 hours, from about 45 minutes to about 18hours, from about 1 hour to about 12 hours, from about 2 hours to about12 hours, from about 4 hours to about 10 hours, or from about 2 hours toabout 8 hours.

The chlorine-containing compound in the chlorine-containing stream canbe any chlorine-containing compound disclosed herein as being suitableas a chlorine-containing compound in the halogen-containing stream. Forinstance, the chlorine-containing compound can comprise (or consistessentially of, or consist of) chlorine gas (Cl₂). In addition tochlorine, the chlorine-containing stream can further comprise an inertgas, such as helium, neon, argon, or nitrogen, or combinations of two ormore of these materials. In certain embodiments, the chlorine-containingstream can comprise (or consist essentially of, or consist of) achlorine-containing compound and an inert gas, and the inert gas can beor can comprise nitrogen. In a further embodiment, thechlorine-containing stream can comprise (or consist essentially of, orconsist of) chlorine gas (Cl₂) and nitrogen.

In certain embodiments, the amount of chlorine (Cl) in thechlorine-containing stream can be less than about 5% by volume. Forinstance, the chlorine-containing stream can comprise a concentration inppmv (ppm by volume) of Cl of less than about 25,000; alternatively, appmv of Cl of less than about 10,000; alternatively, a ppmv of Cl ofless than about 5,000; alternatively, a ppmv of Cl of less than about2,500. Suitable ranges of the concentration of Cl can include, but arenot limited to, the following ranges: from about 50 to about 25,000ppmv, from about 50 to about 5,000 ppmv, from about 50 to about 2,500ppmv, from about 50 to about 1,000 ppmv, from about 250 to about 25,000ppmv, from about 250 to about 10,000 ppmv, from about 250 to about 5,000ppmv, from about 250 to about 2,000 ppmv, from about 500 to about 5,000ppmv, from about 500 to about 2,500 ppmv, and the like.

The chlorine-containing stream can be substantially free ofoxygen-containing compounds (e.g., oxygen (O₂), water (H₂O), etc.),i.e., can contain less than 100 ppmw (ppm by weight) ofoxygen-containing compounds. Therefore, it is contemplated that theamount of oxygen-containing compounds in the chlorine-containing streamcan be less than 50 ppmw, less than 25 ppmw, less than 10 ppmw, lessthan 5 ppmw, or less than 3 ppmw, in certain embodiments. In otherembodiments, the amount of oxygen-containing compounds in thechlorine-containing stream can be in range from about 0.1 to 100 ppmw,from about 0.5 to 100 ppmw, from about 1 to 100 ppmw, from about 0.1 toabout 50 ppmw, from about 0.1 to about 25 ppmw, from about 0.1 to about10 ppmw, or from about 0.1 to about 5 ppmw. While not wishing to bebound by theory, Applicants believe that it can be beneficial to havesubstantially no oxygen added during the chlorination step of the methodof treating a spent catalyst. Moreover, although not required, thechlorine-containing stream can be substantially free offluorine-containing compounds, i.e., can contain less than 100 ppmw (ppmby weight) of fluorine-containing compounds. As above, it iscontemplated that the amount of fluorine-containing compounds in thechlorine-containing stream can be, for instance, less than 50 ppmw, lessthan 10 ppmw, in a range from about 0.1 to 100 ppmw, in a range fromabout 0.1 to about 50 ppmw, or in a range from about 0.1 to about 10ppmw, and the like.

The chlorination step can be conducted at a variety of temperatures andtime periods. For instance, the chlorination step can be conducted at achlorination temperature in a range from about 0° C. to about 500° C.;alternatively, from about 100° C. to about 500° C.; alternatively, fromabout 0° C. to about 400° C.; alternatively, from about 100° C. to about450° C.; alternatively, from about 150° C. to about 350° C.;alternatively, from about 20° C. to about 350° C.; alternatively, fromabout 25° C. to about 300° C.; alternatively, from about 25° C. to about250° C.; alternatively, from about 10° C. to about 100° C.;alternatively, from about 20° C. to about 50° C.; alternatively, fromabout 50° C. to about 280° C.; alternatively, from about 120° C. toabout 320° C.; alternatively, from about 150° C. to about 300° C.;alternatively, from about 150° C. to about 280° C.; or alternatively,from about 170° C. to about 250° C. In these and other embodiments,these temperature ranges also are meant to encompass circumstances wherethe chlorination step is conducted at a series of differenttemperatures, instead of at a single fixed temperature, falling withinthe respective ranges.

The duration of the chlorination step is not limited to any particularperiod of time. Hence, the chlorination step can be conducted, forexample, in a time period ranging from as little as 30-45 minutes to aslong as 12-24 hours, 36-48 hours, or more. The appropriate chlorinationtime can depend upon, for example, the chlorination temperature, and theamount of chlorine in the chlorine-containing stream, among othervariables. Generally, however, the chlorination step can be conducted ina time period that can be in a range from about 45 minutes to about 48hours, such as, for example, from about 1 hour to about 48 hours, fromabout 45 minutes to about 24 hours, from about 45 minutes to about 18hours, from about 1 hour to about 12 hours, from about 2 hours to about12 hours, from about 4 hours to about 10 hours, or from about 2 hours toabout 8 hours.

In various embodiments contemplated herein, the methods of treating orregenerating a spent catalyst can further include an optional halogenpurge step prior to the carbon burn step, and between the fluorinationand chlorination step or between the chlorination and fluorination step.In one embodiment, for example, a method of treating or regenerating aspent catalyst (e.g., comprising a transition metal and a catalystsupport) comprising a fluorination step, followed by a chlorination stepand a carbon burn step, can further comprise a halogen purge step priorto the chlorination step. This halogen purge step can comprisecontacting the fluorinated spent catalyst with a halogen purge streamcomprising (or consisting essentially of, or consisting of) an inertgas. In another embodiment, a method of treating or regenerating a spentcatalyst (e.g., comprising a transition metal and a catalyst support)comprising a chlorination step, followed by a fluorination step and acarbon burn step, can further comprise a halogen purge step prior to thefluorination step. This halogen purge step can comprise contacting thechlorinated spent catalyst with a halogen purge stream comprising (orconsisting essentially of, or consisting of) an inert gas. In thesehalogen purge steps, the inert gas can be helium, neon, argon, ornitrogen, or a mixture thereof; alternatively, helium; alternatively,neon; alternatively, argon; or alternatively, nitrogen.

In some embodiments, the halogen purge stream can be substantially freeof oxygen-containing compounds (e.g., oxygen, water, etc.), as discussedabove in relation to the halogenation step. Hence, the halogen purgestep can be conducted in the presence of less than 100 ppmw ofoxygen-containing compounds, or less than 50 ppmw, or less than 25 ppmw,or less than 10 ppmw, or less than 5 ppmw, or less than 3 ppmw.

Additionally, in some embodiments, the halogen purge stream can besubstantially free of halogen-containing compounds, as discussed hereinin relation to the carbon burn step. Hence, the halogen purge step canbe conducted in the presence of less than 100 ppmw of halogen-containingcompounds, or less than 50 ppmw, or less than 25 ppmw, or less than 10ppmw, or less than 5 ppmw, or less than 3 ppmw.

The halogen purge step can be performed at a halogen purge temperaturewhich generally can encompass the same temperature range as thehalogenation temperature used in the halogenation step. Accordingly, thehalogen purge temperature can be in a range from about 0° C. to about500° C.; alternatively, from about 100° C. to about 500° C.;alternatively, from about 0° C. to about 400° C.; alternatively, fromabout 100° C. to about 400° C.; alternatively, from about 150° C. toabout 400° C.; alternatively, from about 20° C. to about 350° C.;alternatively, from about 25° C. to about 300° C.; alternatively, fromabout 180° C. to about 320° C.; alternatively, from about 180° C. toabout 280° C.; or alternatively, from about 200° C. to about 300° C. Inthese and other embodiments, these temperature ranges also are meant toencompass circumstances where the halogen purge step is conducted at aseries of different temperatures, instead of at a single fixedtemperature, falling within the respective ranges.

The duration of the halogen purge step is not limited to any particularperiod of time. Typically, the halogen purge step can be conducted in atime period ranging from as little as 30-45 minutes to as long as 48-72hours (or more), but more typically, the purging step can be conductedin a time period that can be in a range from about 1 hour to about 48hours, such as, for example, from about 1 hour to about 36 hours, fromabout 2 hours to about 36 hours, from about 2 hours to about 24 hours,or from about 2 hours to about 18 hours.

Alternatively, the halogen purge step can be conducted for a time periodsufficient to reduce the halogen content of the outgoing purging stream,after contacting the spent catalyst (the fluorinated spent catalyst orthe chlorinated spent catalyst), to less than 100 ppmw ofhalogen-containing compounds (i.e., substantially halogen-free). Forinstance, after contacting the spent catalyst with a fluorine-containingstream comprising a fluorine-containing compound to produce afluorinated spent catalyst, the halogen purge step can be conducted fora time period sufficient to reduce the fluorine content of the outgoinghalogen purge stream, after contacting the fluorinated spent catalyst,to less than about 100 ppmw of fluorine-containing compounds;alternatively, less than about 50 ppmw; alternatively, less than about25 ppmw; alternatively, less than about 10 ppmw; alternatively, lessthan about 5 ppmw; or alternatively, less than about 3 ppmw. Likewise,after contacting the spent catalyst with a chlorine-containing streamcomprising a chlorine-containing compound to produce a chlorinated spentcatalyst, the halogen purge step can be conducted for a time periodsufficient to reduce the chlorine content of the outgoing halogen purgestream, after contacting the chlorinated spent catalyst, to less thanabout 100 ppmw of chlorine-containing compounds; alternatively, lessthan about 50 ppmw; alternatively, less than about 25 ppmw;alternatively, less than about 10 ppmw; alternatively, less than about 5ppmw; or alternatively, less than about 3 ppmw.

Step (ii) and step (3) of the method for treating or regenerating aspent catalyst often can be referred to as the carbon burn step, ordecoking step, and in this step, a halogenated spent catalyst (or afluorinated-chlorinated spent catalyst, or a chlorinated-fluorinatedspent catalyst) can be contacted with a decoking gas stream comprisingoxygen. In addition to oxygen, the decoking gas stream can comprise aninert gas, i.e., the decoking gas stream can comprise (or consistessentially of, or consist of) oxygen and an inert gas. Typical inertgasses useful in the carbon burn step can encompass helium, neon, argon,nitrogen, and the like, and this includes combinations of two or more ofthese materials. In certain embodiments, the decoking gas stream cancomprise (or consist essentially of, or consist of) oxygen and nitrogen;alternatively, air and nitrogen; or alternatively, air.

Since the decoking gas stream can comprise air, the decoking gas streamcan comprise about 20-21 mole % oxygen. More often, however, the amountof oxygen in the decoking gas can be less than about 10 mole %. Forexample, in some embodiments, the decoking gas stream can comprise lessthan about 8 mole %, less than about 5 mole %, or less than about 3 mole% oxygen. Accordingly, suitable ranges for the mole % of oxygen in thedecoking gas stream can include, but are not limited to, the followingranges: from about 0.1 to about 25 mole %, from about 0.1 to about 20mole %, from about 0.2 to about 10 mole %, from about 0.2 to about 5mole %, from about 0.3 to about 5 mole %, from about 0.5 to about 5 mole%, from about 0.5 to about 4 mole %, from about 0.5 to about 3 mole %,or from about 1 to about 3 mole %, and the like.

In an embodiment, the decoking gas stream can be substantiallyhalogen-free, i.e., substantially free of halogen-containing compounds.In this context, “substantially halogen-free” means less than 100 ppmw(ppm by weight) of halogen-containing compounds in the decoking gasstream. Therefore, it is contemplated that the amount ofhalogen-containing compounds in the decoking gas stream can be less than50 ppmw, less than 25 ppmw, less than 10 ppmw, less than 5 ppmw, or lessthan 3 ppmw, in certain embodiments. In other embodiments, the amount ofhalogen-containing compounds in the decoking gas stream can be in rangefrom about 0.1 to 100 ppmw, from about 0.5 to 100 ppmw, from about 1 to100 ppmw, from about 0.1 to about 50 ppmw, from about 0.1 to about 25ppmw, from about 0.1 to about 10 ppmw, or from about 0.1 to about 5ppmw. While not wishing to be bound by theory, Applicants believe thatit can be beneficial to have substantially no halogens added during thecarbon burn step of the method of treating a spent catalyst.

In another embodiment, the decoking gas stream can be substantially freeof water, and in this regard, “substantially free” means less than 100ppmw (ppm by weight) of water in the decoking gas stream. Therefore, itis contemplated that the amount of water in the decoking gas stream canbe less than 50 ppmw, less than 25 ppmw, less than 10 ppmw, less than 5ppmw, or less than 3 ppmw, in certain embodiments. In other embodiments,the amount of water in the decoking gas stream can be in range fromabout 0.1 to 100 ppmw, from about 0.5 to 100 ppmw, from about 1 to 100ppmw, from about 0.1 to about 50 ppmw, from about 0.1 to about 25 ppmw,from about 0.1 to about 10 ppmw, or from about 0.1 to about 5 ppmw.While not wishing to be bound by theory, Applicants believe that it canbe beneficial to have substantially no water added during the carbonburn step of the method of treating a spent catalyst.

Similar to that described above for the halogen-containing stream, anycompositional attributes of the decoking gas stream are meant to referto the incoming decoking gas stream, prior to contacting the halogenatedspent catalyst (or the fluorinated-chlorinated spent catalyst, or thechlorinated-fluorinated spent catalyst), unless expressly statedotherwise. As one of skill in the art would readily recognize, theoutgoing decoking gas stream, after contacting the halogenated spentcatalyst (or the fluorinated-chlorinated spent catalyst, or thechlorinated-fluorinated spent catalyst), can vary significantly incomposition from the incoming decoking gas stream. For instance,halogens deposited during the halogenation step (or fluorination and/orchlorination steps) can elute, in some circumstances, from the catalystduring the carbon burn step. Moreover, water can be produced during thecarbon burn step, and thus, water may be detected in the outgoingdecoking stream.

The carbon burn step can be conducted at a variety of temperatures andtime periods. For instance, the carbon burn step can be conducted at apeak decoking temperature in a range from about 300° C. to about 600°C.; alternatively, from about 300° C. to about 550° C.; alternatively,from about 300° C. to about 500° C.; alternatively, from about 320° C.to about 480° C.; alternatively, from about 340° C. to about 460° C.; oralternatively, from about 350° C. to about 450° C. In these and otherembodiments, these temperature ranges also are meant to encompasscircumstances where the carbon burn step is conducted at a series ofdifferent temperatures (e.g., an initial decoking temperature, a peakdecoking temperature), instead of at a single fixed temperature, fallingwithin the respective ranges. For instance, the carbon burn step canstart at an initial decoking temperature which is the same as thehalogenation temperature in the halogenation step (or fluorinationtemperature in the fluorination step, or chlorination temperature in thechlorination step). Thus, for example, the carbon burn step can commenceat an initial decoking temperature in a range from about 25° C. to about250° C., from about 10° C. to about 100° C., or from about 50° C. toabout 280° C. Subsequently, the temperature of the carbon burn step canbe increased to a peak decoking temperature, for example, in a rangefrom about 300° C. to about 600° C., or from about 350° C. to about 450°C.

The duration of the carbon burn step is not limited to any particularperiod of time. Hence, the carbon burn step can be conducted, forexample, in a time period ranging from as little as 30-45 minutes to aslong as 48-72 hours, or more. The appropriate decoking time can dependupon, for example, the initial/peak decoking temperature, and the amountof oxygen in the decoking gas stream, among other variables. Generally,however, the carbon burn step can be conducted in a time period that canbe in a range from about 45 minutes to about 72 hours, such as, forexample, from about 45 minutes to about 48 hours, from about 1 hour toabout 48 hours, from about 1 hour to about 12 hours, or from about 1hour to about 6 hours.

Alternatively, the carbon burn step can be conducted for a time periodsufficient to reduce the wt. % of carbon on the halogenated spentcatalyst (or the fluorinated-chlorinated spent catalyst, or thechlorinated-fluorinated spent catalyst) to less than about 1 wt. %. Insome embodiments, the carbon burn step can be conducted for a timeperiod sufficient to reduce the wt. % of carbon on the halogenated spentcatalyst (or the fluorinated-chlorinated spent catalyst, or thechlorinated-fluorinated spent catalyst) to less than about 0.75 wt. %,less than about 0.5 wt. %, or less than about 0.25 wt. %. In otherembodiments, the carbon burn step can be conducted for a time perioddetermined by monitoring the CO₂ level in the outgoing or exitingdecoking stream, after contacting the catalyst. Hence, the carbon burnstep can be conducted for a time period sufficient to reduce the amountof CO₂ in the outgoing or exiting decoking stream, after contacting thecatalyst, to less than about 100 ppmv, for example, less than about 50ppmv, or less than about 20 ppmv.

Alternatively, the carbon burn step can be conducted for a time periodsufficient to result in a treated spent catalyst having an activity thatis from about 50% to about 80% of the activity of the fresh catalyst,for example, from about 50% to about 75%, or from about 55% to about75%. In this regard, the activity of the treated spent catalyst is basedon returning to within about 50%-80% of fresh catalyst activity of thesame production run of catalyst, tested on the same equipment and underthe same method and conditions.

In various embodiments contemplated herein, the methods of treating orregenerating a spent catalyst can further include one or more optionalsteps performed prior to the halogenation step (or prior to thefluorination and chlorination steps, or prior to the chlorination andfluorination steps) and the carbon burn step. For example, a method oftreating or regenerating a spent catalyst can further comprise a partialdecoking step prior to the halogenation (or fluorination, orchlorination) step, and/or can further comprise a pre-drying step priorto the halogenation (or fluorination, or chlorination) step, and/or canfurther comprise a re-coking pretreatment step prior to the halogenation(or fluorination, or chlorination) step. These optional pre-halogenation(or pre-fluorination, or pre-chlorination) steps are discussed ingreater detail herein below. In one embodiment, at least one of theseoptional steps can be performed in a method of treating or regeneratinga spent catalyst, while in another embodiment, two of these optionalsteps can be performed. However, in yet another embodiment, all three ofthese optional steps can be performed. The pre-halogenation (orpre-fluorination, or pre-chlorination) steps can be performed in anyorder, however, in a particular embodiment, the partial decoking stepcan be performed first, followed by the pre-drying step, and then there-coking step.

In an embodiment, a method of treating or regenerating a spent catalyst(e.g., comprising a transition metal and a catalyst support) comprisinga halogenation step (or a fluorination step followed a chlorinationstep, or a chlorination step followed by a fluorination step) and acarbon burn step can further comprise a partial decoking step prior tothe halogenation (or fluorination, or chlorination) step. This partialdecoking step generally can comprise contacting the spent catalyst witha partial decoking gas stream comprising oxygen.

The composition of the partial decoking gas stream can encompass thesame potential attributes as that described above for the decoking gasstream employed in the carbon burn step. Thus, in addition to oxygen,the partial decoking gas stream can comprise an inert gas, such ashelium, neon, argon, and/or nitrogen. In an embodiment, the partialdecoking gas stream can comprise (or consist essentially of, or consistof) oxygen and nitrogen; alternatively, air and nitrogen; oralternatively, air. In another embodiment, the partial decoking gasstream often can comprise, for example, from about 0.1 to about 25 mole% oxygen, from about 0.1 to about 20 mole % oxygen, from about 0.2 toabout 10 mole % oxygen, from about 0.2 to about 5 mole % oxygen, fromabout 0.3 to about 5 mole % oxygen, from about 0.5 to about 5 mole %oxygen, from about 0.5 to about 4 mole % oxygen, from about 0.5 to about3 mole % oxygen, or from about 1 to about 3 mole % oxygen, and the like.In yet another embodiment, the partial decoking gas stream can besubstantially halogen-free or substantially free of halogen-containingcompounds, i.e., having less than 100 ppmw (ppm by weight) ofhalogen-containing compounds in the partial decoking gas stream, suchas, for example, less than 50 ppmw, less than 25 ppmw, less than 10ppmw, less than 5 ppmw, or less than 3 ppmw, of halogen-containingcompounds in the partial decoking gas stream. In still anotherembodiment, the partial decoking gas stream can be substantially free ofwater, i.e., having less than 100 ppmw of water in the partial decokinggas stream, such as, for example, less than 50 ppmw, less than 25 ppmw,less than 10 ppmw, less than 5 ppmw, or less than 3 ppmw, of water inthe partial decoking gas stream.

The partial decoking step differs from the carbon burn step in that itcan be conducted at a much lower temperature. Generally, the partialdecoking step can be conducted at a partial decoking temperature in arange from about from about 125° C. to about 260° C.; alternatively,from about 150° C. to about 250° C.; alternatively, from about 150° C.to about 250° C.; alternatively, from about 175° C. to about 250° C.;alternatively, from about 150° C. to about 225° C.; or alternatively,from about 175° C. to about 225° C. In these and other embodiments,these temperature ranges also are meant to encompass circumstances wherethe partial decoking step is conducted at a series of differenttemperatures, instead of at a single fixed temperature, falling withinthe respective ranges.

The duration of the partial decoking step is not limited to anyparticular period of time. Typically, the partial decoking step can beconducted in a time period ranging from as little as 30-45 minutes to aslong as 48 hours (or more), but more typically, the partial decokingstep can be conducted in a time period that can be in a range from about1 hour to about 36 hours, such as, for example, from about 2 hours toabout 36 hours, from about 1 hour to about 24 hours, from about 1 hourto about 18 hours, or from about 2 hours to about 24 hours.

Alternatively, the partial decoking step can be conducted for a timeperiod sufficient to reduce the wt. % of carbon on the spent catalyst towithin a range from about 1 to about 10 wt. %, such as, for example,from about 2 to about 10 wt. %, from about 2 to about 8 wt. %, fromabout 3 to about 7 wt. %, from about 3 to about 6 wt. %, or from about 4to about 5 wt. % carbon. While not wishing to be bound by theory,Applicants believe that operational health and safety benefits can beachieved by removing liquid hydrocarbons and light oligomers prior totreating the spent catalyst or opening the reactor.

In an embodiment, a method of treating or regenerating a spent catalyst(e.g., comprising a transition metal and a catalyst support) comprisinga halogenation step (or a fluorination step followed a chlorinationstep, or a chlorination step followed by a fluorination step) and acarbon burn step can further comprise a pre-drying step prior to thehalogenation (or fluorination, or chlorination) step. This pre-dryingstep generally can comprise contacting the spent catalyst with apre-drying gas stream comprising (or consisting essentially of, orconsisting of) an inert gas. The inert gas can be helium, neon, argon,or nitrogen, or a mixture thereof; alternatively, helium; alternatively,neon; alternatively, argon; or alternatively, nitrogen. Additionally, insome embodiments, the pre-drying gas stream can be substantially free ofoxygen-containing compounds (e.g., oxygen, water, etc), as discussedabove in relation to the halogenation step. Hence, the pre-drying stepcan be conducted in the presence of less than 100 ppmw ofoxygen-containing compounds, or less than 50 ppmw, or less than 25 ppmw,or less than 10 ppmw, or less than 5 ppmw, or less than 3 ppmw.

The pre-drying step can be performed at a pre-drying temperature whichgenerally can encompass the same temperature range as the halogenationtemperature used in the halogenation step. Accordingly, the pre-dryingtemperature can be in a range from about 0° C. to about 500° C.;alternatively, from about 100° C. to about 500° C.; alternatively, fromabout 0° C. to about 400° C.; alternatively, from about 100° C. to about400° C.; alternatively, from about 150° C. to about 400° C.;alternatively, from about 20° C. to about 350° C.; alternatively, fromabout 25° C. to about 300° C.; alternatively, from about 150° C. toabout 350° C.; alternatively, from about 180° C. to about 320° C.;alternatively, from about 180° C. to about 280° C.; or alternatively,from about 200° C. to about 300° C.

In these and other embodiments, these temperature ranges also are meantto encompass circumstances where the pre-drying step is conducted at aseries of different temperatures, instead of at a single fixedtemperature, falling within the respective ranges.

The duration of the pre-drying step is not limited to any particularperiod of time. Typically, the pre-drying step can be conducted in atime period ranging from as little as 30-45 minutes to as long as 48-72hours (or more), but more typically, the pre-drying step can beconducted in a time period that can be in a range from about 1 hour toabout 72 hours, such as, for example, from about 1 hour to about 48hours, from about 1 hour to about 36 hours, from about 2 hours to about24 hours, or from about 2 hours to about 18 hours.

Alternatively, the pre-drying step can be conducted for a time periodsufficient to reduce the moisture content of the spent catalyst to lessthan about 4 wt. %, less than about 2 wt. %, less than about 1 wt. %,less than about 0.5 wt. %, or less than about 0.1 wt %.

In an embodiment, a method of treating or regenerating a spent catalyst(e.g., comprising a transition metal and a catalyst support) comprisinga halogenation step (or a fluorination step followed a chlorinationstep, or a chlorination step followed by a fluorination step) and acarbon burn step can further comprise a re-coking pretreatment stepprior to the halogenation (or fluorination, or chlorination) step. Thisre-coking pretreatment step generally can comprise contacting the spentcatalyst with a pretreatment stream comprising a hydrocarbon feed andmolecular hydrogen. The hydrocarbon feed can be the same as a feedstream to an aromatization process. Thus, in some embodiments, thehydrocarbon feed can comprise C₆-C₈ alkanes and/or cycloalkanes.

The pretreatment step can be performed at a pretreatment temperaturewhich generally can encompass the same temperature range as thehalogenation temperature and/or the temperature used in thearomatization process. Accordingly, the pretreatment temperature can bein a range from about 100° C. to about 600° C.; alternatively, fromabout 300° C. to about 600° C.; alternatively, from about 400° C. toabout 600° C.; alternatively, from about 100° C. to about 350° C.;alternatively, from about 0° C. to about 400° C.; alternatively, fromabout 20° C. to about 350° C.; alternatively, from about 25° C. to about300° C.; alternatively, from about 120° C. to about 300° C.; oralternatively, from about 150° C. to about 250° C. In these and otherembodiments, these temperature ranges also are meant to encompasscircumstances where the pretreatment step is conducted at a series ofdifferent temperatures, instead of at a single fixed temperature,falling within the respective ranges.

The duration of the re-coking pretreatment step is not limited to anyparticular period of time. Typically, the pretreatment step can beconducted in a time period ranging from as little as 30-45 minutes to aslong as 48-72 hours (or more), but more typically, the pretreatment stepcan be conducted in a time period that can be in a range from about 1hour to about 48 hours, such as, for example, from about 1 hour to about36 hours, from about 1 hour to about 24 hours, from about 2 hours toabout 24 hours, or from about 2 hours to about 18 hours.

Alternatively, the re-coking pretreatment step can be conducted for atime period until the wt. % of carbon on the spent catalyst is within arange from about 1 to about 10 wt. %. Additionally or alternatively, there-coking pretreatment step can be conducted for a time periodsufficient to add from about 0.5 to about 2.5 wt. %, from about 1 toabout 2 wt. %, or from about 1 to about 1.5 wt. %, of coke orcarbonaceous build-up onto the spent catalyst.

In various embodiments contemplated herein, the methods of treating orregenerating a spent catalyst can further include one or more optionalintermediate steps performed after the halogenation step (or after thefluorination and chlorination steps, or after the chlorination andfluorination steps), but prior to the carbon burn step. For example, amethod of treating or regenerating a spent catalyst can further comprisea purging step prior to the carbon burn step and/or can further comprisea hydrocarbon treatment step prior to the carbon burn step. Theseoptional intermediate steps are discussed in greater detail hereinbelow. In one embodiment, at least one of these optional intermediatesteps can be performed in a method of treating or regenerating a spentcatalyst, while in another embodiment, both of these optionalintermediate steps can be performed. When both intermediate steps areperformed, the intermediate steps can be performed in any order, forexample, the halogenation step (or the fluorination and chlorinationsteps, or the chlorination and fluorination steps), followed by thehydrocarbon treatment step, then the purging step, and then the carbonburn step.

In an embodiment, a method of treating or regenerating a spent catalyst(e.g., comprising a transition metal and a catalyst support) comprisinga halogenation step (or a fluorination step followed a chlorinationstep, or a chlorination step followed by a fluorination step) and acarbon burn step can further comprise a purging step prior to the carbonburn step. This purging step can comprise contacting the halogenatedspent catalyst (or the fluorinated-chlorinated spent catalyst, or thechlorinated-fluorinated spent catalyst) with a purging stream comprising(or consisting essentially of, or consisting of) an inert gas. The inertgas can be helium, neon, argon, or nitrogen, or a mixture thereof;alternatively, helium; alternatively, neon; alternatively, argon; oralternatively, nitrogen.

Additionally, in some embodiments, the purging stream can besubstantially free of oxygen-containing compounds (e.g., oxygen, water,etc), as discussed above in relation to the halogenation step. Hence,the purging step can be conducted in the presence of less than 100 ppmwof oxygen-containing compounds, or less than 50 ppmw, or less than 25ppmw, or less than 10 ppmw, or less than 5 ppmw, or less than 3 ppmw.

Additionally, in some embodiments, the purging stream can besubstantially free of halogen-containing compounds, as discussed abovein relation to the carbon burn step. Hence, the purging step can beconducted in the presence of less than 100 ppmw of halogen-containingcompounds, or less than 50 ppmw, or less than 25 ppmw, or less than 10ppmw, or less than 5 ppmw, or less than 3 ppmw.

The purging step can be performed at a purging temperature whichgenerally can encompass the same temperature range as the halogenationtemperature used in the halogenation step. Accordingly, the purgingtemperature can be in a range from about 0° C. to about 500° C.;alternatively, from about 100° C. to about 500° C.; alternatively, fromabout 0° C. to about 400° C.; alternatively, from about 100° C. to about400° C.; alternatively, from about 150° C. to about 400° C.;alternatively, from about 20° C. to about 350° C.; alternatively, fromabout 25° C. to about 300° C.; alternatively, from about 180° C. toabout 320° C.; alternatively, from about 180° C. to about 280° C.; oralternatively, from about 200° C. to about 300° C. In these and otherembodiments, these temperature ranges also are meant to encompasscircumstances where the purging step is conducted at a series ofdifferent temperatures, instead of at a single fixed temperature,falling within the respective ranges.

The duration of the purging step is not limited to any particular periodof time. Typically, the purging step can be conducted in a time periodranging from as little as 30-45 minutes to as long as 48-72 hours (ormore), but more typically, the purging step can be conducted in a timeperiod that can be in a range from about 1 hour to about 48 hours, suchas, for example, from about 1 hour to about 36 hours, from about 2 hoursto about 36 hours, from about 2 hours to about 24 hours, or from about 2hours to about 18 hours.

Alternatively, the purging step can be conducted for a time periodsufficient to reduce the halogen content of the outgoing purging stream,after contacting the halogenated spent catalyst (or thefluorinated-chlorinated spent catalyst, or the chlorinated-fluorinatedspent catalyst), to less than 100 ppmw of halogen-containing compounds(i.e., substantially halogen-free). In some embodiments consistent withthe disclosure herein, the halogen content of the outgoing purgingstream, after contacting the halogenated spent catalyst (or thefluorinated-chlorinated spent catalyst, or the chlorinated-fluorinatedspent catalyst), can be less than 50 ppmw, less than 25 ppmw, less than10 ppmw, less than 5 ppmw, or less than 3 ppmw. While not wishing to bebound by theory, Applicants believe that it can be beneficial to havehalogens closely associated with the catalyst during the carbon burnstep, but substantially no halogens present in the free volume of theatmosphere surrounding the halogenated spent catalyst, or thefluorinated-chlorinated spent catalyst, or the chlorinated-fluorinatedspent catalyst (e.g., in the vessel containing the spent catalyst).

In an embodiment, a method of treating or regenerating a spent catalyst(e.g., comprising a transition metal and a catalyst support) comprisinga halogenation step (or a fluorination step followed a chlorinationstep, or a chlorination step followed by a fluorination step) and acarbon burn step can further comprise a hydrocarbon treatment step priorto the carbon burn step. This hydrocarbon treatment step can comprisecontacting the halogenated spent catalyst (or thefluorinated-chlorinated spent catalyst, or the chlorinated-fluorinatedspent catalyst) with a hydrocarbon treatment stream comprising ahydrocarbon feed. The hydrocarbon treatment stream can be the same as afeed stream to an aromatization process. Hence, in some embodiments, thehydrocarbon treatment stream can comprise C₆-C₈ alkanes and/orcycloalkanes.

The hydrocarbon treatment step can be performed at a hydrocarbontreatment temperature which generally can encompass the same temperaturerange as the temperature range used in the aromatization process. Insome embodiments, the hydrocarbon treatment temperature can be in arange from about 300° C. to about 600° C.; alternatively, from about350° C. to about 600° C.; alternatively, from about 400° C. to about600° C.; alternatively, from about 350° C. to about 550° C.; oralternatively, from about 450° C. to about 550° C. In these and otherembodiments, these temperature ranges also are meant to encompasscircumstances where the hydrocarbon treatment step is conducted at aseries of different temperatures, instead of at a single fixedtemperature, falling within the respective ranges.

The duration of the hydrocarbon treatment step is not limited to anyparticular period of time. Typically, the hydrocarbon treatment step canbe conducted in a time period ranging from as little as 30-45 minutes toas long as 48-72 hours (or more), but more typically, the hydrocarbontreatment step can be conducted in a time period that can be in a rangefrom about 1 hour to about 48 hours, such as, for example, from about 1hour to about 36 hours, from about 1 hour to about 24 hours, from about2 hours to about 24 hours, or from about 2 hours to about 18 hours.

In various embodiments contemplated herein, the methods of treating orregenerating a spent catalyst can further include one or more optionalfinal steps performed after the carbon burn step. For example, a methodof treating or regenerating a spent catalyst can further comprise areducing step after the carbon burn step. This reducing step cancomprise contacting the de-coked catalyst with a reducing gas streamcomprising molecular hydrogen. In addition to molecular hydrogen, thereducing gas stream can comprise an inert gas, i.e., the reducing gasstream can comprise (or consist essentially of, or consist of) molecularhydrogen and an inert gas. Typical inert gasses useful in the reducingstep can encompass helium, neon, argon, nitrogen, and the like, and thisincludes combinations of two or more of these materials. In certainembodiments, the reducing gas stream can comprise (or consistessentially of, or consist of) molecular hydrogen and nitrogen.

In some embodiments, molecular hydrogen can be the major component ofthe reducing gas stream, while in other embodiments, molecular hydrogencan be a minor component. For example, the reducing gas stream cancomprise at least about 25 mole % molecular hydrogen, at least about 35mole % molecular hydrogen, at least about 50 mole % molecular hydrogen,at least about 65 mole % molecular hydrogen, at least about 75 mole %molecular hydrogen, or 100 mole % molecular hydrogen. Accordingly,suitable ranges for the mole % of molecular hydrogen in the reducing gasstream can include, but are not limited to, the following ranges: fromabout 25 to 100 mole %, from about 50 to 100 mole %, from about 25 to100 mole %, from about 35 to 100 mole %, from about 55 to 100 mole %,from about 25 to about 75 mole %, from about 35 to about 65 mole %, orfrom about 70 to 100 mole %, and the like.

The reducing step can be conducted at a variety of temperatures and timeperiods. For instance, the reducing step can be conducted at a peakreducing temperature in a range from about 300° C. to about 600° C.;alternatively, from about 300° C. to about 550° C.; alternatively, fromabout 400° C. to about 600° C.; alternatively, from about 350° C. toabout 575° C.; alternatively, from about 400° C. to about 550° C.; oralternatively, from about 450° C. to about 550° C. In these and otherembodiments, these temperature ranges also are meant to encompasscircumstances where the reducing step is conducted at a series ofdifferent temperatures (e.g., an initial reducing temperature, a peakreducing temperature), instead of at a single fixed temperature, fallingwithin the respective ranges. For instance, the reducing step can startat an initial reducing temperature which is the same as the halogenationtemperature in the halogenation step, or the fluorination temperature inthe fluorination step, or the chlorination temperature in thechlorination step (e.g., in a range from about 0° C. to about 500° C.,in a range from about 25° C. to about 250° C., or in a range from about50° C. to about 280° C.). Subsequently, the temperature of the reducingstep can be increased to a peak reducing temperature, for example, in arange from about 400° C. to about 600° C.

The duration of the reducing step is not limited to any particularperiod of time. Hence, the reducing step can be conducted, for example,in a time period ranging from as little as 1 hour to as long as 48-72hours, or more. For example, the reducing step can be conducted in atime period that can be in a range from about 2 hours to about 48 hours,from about 3 hours to about 36 hours, from about 5 hours to about 36hours, from about 2 hours to about 30 hours, or from about 10 hours toabout 30 hours.

Alternatively, the reducing step can be conducted for a time periodsufficient to result in a treated spent catalyst having an activity thatis from about 50% to about 80% of the activity of the fresh catalyst,for example, from about 50% to about 75%, or from about 55% to about75%. In this regard, the activity of the treated spent catalyst is basedon returning to within about 50%-80% of fresh catalyst activity of thesame production run of catalyst, tested on the same equipment and underthe same method and conditions.

Reforming Processes with Aromatization Catalysts

Also encompassed herein are various processes for reforminghydrocarbons. One such reforming process can comprise (or consistessentially of, or consist of):

(a) contacting a hydrocarbon feed with an aromatization catalystcomprising a transition metal and a catalyst support under reformingconditions in a reactor system to produce an aromatic product;

(b) performing step (a) for a time period sufficient to form a spentaromatization catalyst;

(c) contacting the spent aromatization catalyst with ahalogen-containing stream comprising chlorine and fluorine to produce ahalogenated spent catalyst; and

(d) contacting the halogenated spent catalyst with a decoking gas streamcomprising oxygen.

Generally, the features of any of the reforming processes disclosedherein (e.g., the hydrocarbon feed, the aromatization catalyst, thetransition metal, the catalyst support, the reforming conditions, thehalogen-containing stream, the conditions under which the halogenationstep is conducted, the decoking gas stream, the conditions under whichthe decoking step is conducted, among others) are independentlydescribed herein, and these features can be combined in any combinationto further describe the disclosed processes. Moreover, other processsteps can be conducted before, during, and/or after any of the stepslisted in the disclosed processes, unless stated otherwise.

The halogenation step (c) and the carbon burn step (d) are discussedherein above. Any embodiments and features of the halogenation stepand/or the carbon burn step (as well as other steps that can beconducted before, during and/or after the halogenation step and/or thecarbon burn step) described herein can be utilized in the processes forreforming hydrocarbons and, accordingly, are encompassed herein.

Another process for reforming hydrocarbons disclosed herein can comprise(or consist essentially of, or consist of):

(A) contacting a hydrocarbon feed with an aromatization catalystcomprising a transition metal and a catalyst support under reformingconditions in a reactor system to produce an aromatic product;

(B) performing step (A) for a time period sufficient to form a spentaromatization catalyst;

(C) contacting the spent aromatization catalyst with afluorine-containing stream comprising a fluorine-containing compound toproduce a fluorinated spent catalyst;

(D) contacting the fluorinated spent catalyst with a chlorine-containingstream comprising a chlorine-containing compound to produce afluorinated-chlorinated spent catalyst; and

(E) contacting the fluorinated-chlorinated spent catalyst with adecoking gas stream comprising oxygen.

Yet another process for reforming hydrocarbons disclosed herein cancomprise (or consist essentially of, or consist of):

(A) contacting a hydrocarbon feed with an aromatization catalystcomprising a transition metal and a catalyst support under reformingconditions in a reactor system to produce an aromatic product;

(B) performing step (A) for a time period sufficient to form a spentaromatization catalyst;

(C) contacting the spent aromatization catalyst with achlorine-containing stream comprising a chlorine-containing compound toproduce a chlorinated spent catalyst;

(D) contacting the chlorinated spent catalyst with a fluorine-containingstream comprising a fluorine-containing compound to produce achlorinated-fluorinated spent catalyst; and

(E) contacting the chlorinated-fluorinated spent catalyst with adecoking gas stream comprising oxygen.

Generally, the features of any of the reforming processes disclosedherein (e.g., the hydrocarbon feed, the aromatization catalyst, thetransition metal, the catalyst support, the reforming conditions, thefluorine-containing stream, the conditions under which the fluorinationstep is conducted, the chlorine-containing stream, the conditions underwhich the chlorination step is conducted, the decoking gas stream, theconditions under which the decoking step is conducted, among others) areindependently described herein, and these features can be combined inany combination to further describe the disclosed processes. Moreover,other process steps can be conducted before, during, and/or after any ofthe steps listed in the disclosed processes, unless stated otherwise.

The fluorination and chlorination steps (steps (C) and (D)) and thecarbon burn step (E) are discussed herein above. Any embodiments andfeatures of the fluorination step and/or the chlorination step and/orthe carbon burn step (as well as other steps that can be conductedbefore, during and/or after the fluorination step and/or thechlorination step and/or the carbon burn step) described herein can beutilized in the processes for reforming hydrocarbons and, accordingly,are encompassed herein.

In these reforming processes, step (a) and step (A) can comprisecontacting a hydrocarbon feed with an aromatization catalyst underreforming conditions in a reactor system to produce an aromatic product.The reactor systems for reforming and the respective reformingconditions are well known to those of skill in the art and aredescribed, for example, in U.S. Pat. Nos. 4,456,527, 5,389,235,5,401,386, 5,401,365, 6,207,042, and 7,932,425, the disclosures of whichare incorporated herein by reference in their entirety.

Likewise, typical hydrocarbon feeds are disclosed in these references.Often, the hydrocarbon feed can be a naptha stream or light napthastream. In certain embodiments, the hydrocarbon feed can comprise C₆-C₈alkanes and/or cycloalkanes (e.g., hexane, cyclohexane, etc.).

Step (b) and step (B) in the reforming processes indicate that step (a)and step (A), respectively, can be performed for a time periodsufficient for the aromatization catalyst to be “spent.” As discussedherein above, a “spent” catalyst is typically a catalyst that hasunacceptable performance in one or more of catalyst activity,hydrocarbon feed conversion, yield to a desired product(s), selectivityto a desired product(s), or an operating parameter, such asoutput/production rate or reforming temperature, although not limitedthereto. Once the aromatization catalyst is “spent,” the rejuvenationsteps (c) and (d) (or (C), (D), and (E)), amongst others, can beperformed.

In an embodiment, the reforming process can be an in situ process, forexample, steps (a)-(d) or (A)-(E) can be performed in the same reactorsystem. However, in an alternative embodiment, the catalyst treatment orrejuvenation steps (c)-(d) or (C)-(E) can be conducted external to thereactor system, such as in another vessel and/or location. For instance,the halogenation (or fluorination and chlorination) and the carbon burnsteps can be conducted in a vessel that is not in the reforming reactorsystem.

In another embodiment, the reforming process can further comprise a stepof reactivating the catalyst after step (d) or after step (E). Anycatalyst reactivated by these processes is considered within the scopeof this disclosure and encompassed herein. In some embodiments, thereactivated catalyst can have from about 50% to about 80% of thecatalyst activity of fresh aromatization catalyst of the same productionrun of catalyst, tested on the same equipment, and under the same methodand test conditions.

Additionally, it is contemplated that the fouling rate (FR) of thereactivated catalyst can be equal to or less than the fouling rate ofthe fresh aromatization catalyst. Moreover, the End of Run (EOR)temperature of the reactivated catalyst can be within +/−8° C. of theEOR temperature of the fresh aromatization catalyst, in certainembodiments.

Transition Metal Based Catalysts

Consistent with embodiments disclosed herein, and the various methodsdescribed herein above and below, the aromatization catalyst (e.g.,fresh or spent) can comprise a transition metal and a catalyst support.The catalyst support typically can comprise an inorganic oxide, examplesof which can include, but are not limited to, bound medium and/or largepore zeolites (aluminosilicates), amorphous inorganic oxides, as well asmixtures thereof. Large pore zeolites often can have average porediameters in a range of from about 7 Å to about 12 Å, and non-limitingexamples of large pore zeolites include L-zeolite, Y-zeolite, mordenite,omega zeolite, beta zeolite, and the like. Medium pore zeolites oftencan have average pore diameters in a range of from about 5 Å to about 7Å. Amorphous inorganic oxides can include, but are not limited to,aluminum oxide, silicon oxide, titania, and combinations thereof.

The term “zeolite” generally refers to a particular group of hydrated,crystalline metal aluminosilicates. These zeolites exhibit a network ofSiO₄ and AlO₄ tetrahedra in which aluminum and silicon atoms arecrosslinked in a three-dimensional framework by sharing oxygen atoms. Inthe framework, the ratio of oxygen atoms to the total of aluminum andsilicon atoms can be equal to 2. The framework exhibits a negativeelectrovalence that typically can be balanced by the inclusion ofcations within the crystal, such as metals, alkali metals, alkalineearth metals, and/or hydrogen.

In some embodiments, the catalyst support can comprise an L-typezeolite. L-type zeolite supports are a sub-group of zeolitic supports,which can contain mole ratios of oxides in accordance with the formula:M_(2/n)OAl₂O₃xSiO₂yH₂O. In this formula, “M” designates an exchangeablecation (one or more) such as barium, calcium, cerium, lithium,magnesium, potassium, sodium, strontium, and/or zinc, as well asnon-metallic cations like hydronium and ammonium ions, which may bereplaced by other exchangeable cations without causing a substantialalteration of the basic crystal structure of the L-type zeolite. The “n”in the formula represents the valence of “M”; “x” is 2 or greater; and“y” is the number of water molecules contained in the channels orinterconnected voids of the zeolite.

In one embodiment, the catalyst support can comprise a bound potassiumL-type zeolite, also referred to as a KL-zeolite, while in anotherembodiment, the catalyst support can comprise a barium ion-exchangedL-zeolite. As used herein, the term “KL-zeolite” refers to L-typezeolites in which the principal cation M incorporated in the zeolite ispotassium. A KL-zeolite can be cation-exchanged (e.g., with barium) orimpregnated with a transition metal and one or more halides to produce atransition metal impregnated, halided zeolite or a KL supportedtransition metal-halide zeolite catalyst.

In the aromatization catalyst (e.g., fresh or spent), the zeolite can bebound with a support matrix (or binder), non-limiting examples of whichcan include silica, alumina, magnesia, boria, titania, zirconia, variousclays, and the like, including mixed oxides thereof, as well as mixturesthereof. For example, the spent catalyst can comprise a support matrixcomprising alumina, silica, a mixed oxide thereof, or a mixture thereof.The zeolite can be bound with the support matrix using any method knownin the art.

The aromatization catalyst can comprise a transition metal, andnon-limiting examples of suitable transition metals can include iron,cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium,platinum, gold, silver, copper, and the like, or a combination of two ormore transition metals. In one embodiment, the transition metal cancomprise a Group VIII transition metal (one or more), while in anotherembodiment, the transition metal can comprise platinum (Pt).

In one embodiment, the spent catalyst can comprise from about 0.1 wt. %to about 10 wt. % transition metal. In another embodiment, the spentcatalyst can comprise from about 0.3 wt. % to about 5 wt. % transitionmetal. In yet another embodiment, the spent catalyst can comprise fromabout 0.3 wt. % to about 3 wt. % transition metal, or from about 0.5 wt.% to about 2 wt. % transition metal. These weight percentages are basedon the weight of the spent catalyst excluding carbon. As one of skill inthe art would recognize, the spent catalyst can contain varying levelsof carbon build-up, often in the 2 wt. % to 10 wt. % range. Accordingly,the weight percentages of the transition metal are meant to be based onthe weight of the spent catalyst minus any weight attributable tocarbon.

In circumstances where the transition metal comprises platinum, thespent catalyst can comprise from about 0.1 wt. % to about 10 wt. %platinum; alternatively, from about 0.3 wt. % to about 5 wt. % platinum;alternatively, from about 0.3 wt. % to about 3 wt. % platinum; oralternatively, from about 0.5 wt. % to about 2 wt. % platinum. In aparticular embodiment contemplated herein, the spent catalyst cancomprise platinum on a KL-zeolite.

While not being limited thereof, the spent catalyst can comprise fromabout 5 wt. % to about 35 wt. % support matrix. For example, the spentcatalyst can comprise from about 5 wt. % to about 30 wt. %, or fromabout 10 wt. % to about 30 wt. % support matrix. Similar to above, theseweight percentages are based on the weight of the spent catalystexcluding any weight contribution due to carbon.

In an embodiment, the aromatization catalyst can further comprise ahalogen, such as chlorine, fluorine, bromine, iodine, or a combinationof two or more halogens. For example, the spent catalyst can comprisechlorine, or fluorine, or both chlorine and fluorine. Chlorine can bepresent in the spent catalyst in an amount of from about 0.025 wt. % toabout 5 wt. %, from about 0.025 wt. % to about 3 wt. %, or from about0.05 wt. % to about 2 wt. %. Likewise, the spent catalyst can comprisefrom about 0.025 wt. % to about 5 wt. % fluorine, from about 0.025 wt. %to about 3 wt. % fluorine, or from about 0.05 wt. % to about 2 wt. %fluorine. These weight percentages are based on the weight of the spentcatalyst, and exclude any weight contribution due to carbon. In certainembodiments, the spent catalyst comprises chlorine and fluorine, andtypically, the molar ratio of chlorine:fluorine can be in the range offrom about 0.5:1 to about 4:1. Other suitable molar ratios of Cl:F caninclude the following non-limiting ranges: from about 1:1 to about 4:1,from about 0.5:1 to about 3:1, from about 1:1 to about 3:1, from about0.5:1 to about 2:1, or from about 1:1 to about 2.5:1.

Examples of representative and non-limiting catalysts that areencompassed herein include those disclosed in U.S. Pat. Nos. 5,196,631,6,190,539, 6,406,614, 6,518,470, 6,812,180, and 7,153,801, thedisclosures of which are incorporated herein by reference in theirentirety.

EXAMPLES

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, embodiments, modifications,and equivalents thereof which, after reading the description herein, cansuggest themselves to one of ordinary skill in the art without departingfrom the spirit of the present invention or the scope of the appendedclaims.

Treated or rejuvenated catalysts in some of the examples that followwere tested for their respective fouling rates (abbreviated FR, units ofm° F./hr), which correlate to their activities by the formula,y=FR*t+SOR, where y is temperature, FR is the fouling rate, t is time,and SOR is the initial Start of Run temperature. The FR of a treated orrejuvenated catalyst sample was determined by plotting the temperaturerequired to maintain a total yield of benzene and toluene at 60 wt. %over time at standard test conditions, as described later herein. TheFR's were then determined from the calculated slopes fit to theresulting data. The total Time on Stream (abbreviated TOS, units of hr)and the End of Run temperature (abbreviated EOR) also were determined.

In each of the examples, the following standard testing procedures wereutilized. The catalysts were ground and sieved to about 20-40 mesh, and1 g of the sieved catalyst was placed in a ¼-inch OD stainless steelreactor vessel in a temperature controlled furnace. After reducing thecatalyst under flowing molecular hydrogen, a feed stream of aliphatichydrocarbons and molecular hydrogen was introduced to the reactor vesselat a feed rate of 22 mL/min, a pressure of 50 psig, a H₂:hydrocarbonmolar ratio of 3:1, and a liquid hourly space velocity (LHSV) of 9 hr⁻¹to obtain catalyst performance data over time. The aliphatic hydrocarbonfeed contained from 22 to 26 wt. % n-hexane, 4 to 8 wt. % n-heptane, 33to 37 wt. % C₆ iso-paraffins, 17 to 21 wt. % C₇ iso-paraffins, 6 to 10wt. % C₈ iso-paraffins, with the balance attributable to C₆ and C₇olefins, naphthenes, and aromatics. The reactor effluent composition wasanalyzed by gas chromatography to determine the amount of benzene andtoluene.

Examples 1-47

In Examples 1-47, experiments were conducted to demonstrate theeffectiveness of various processes and steps in treating andrejuvenating a spent aromatization catalyst, with the performance of afresh aromatization catalyst used as a target baseline. The fresharomatization catalyst was a Pt/KL-zeolite containing approximately 1wt. % platinum, and 0.828 wt. % Cl and 0.837 wt. % F (determined viaXRF), with a surface area of approximately 177.5 m²/g, a pore volume of0.19 cc/g, and a micropore volume of 0.0615 cc/g. The source of thespent catalyst was the fresh catalyst, but after it had been deactivatedafter long-term use in an aromatization process. Prior to usage in theseexamples, the spent aromatization catalyst was subjected to a mildpartial decoking treatment to remove unreacted hydrocarbons and lightcarbonaceous deposits from the catalyst.

The general treating or rejuvenating procedure was conducted as follows.Approximately 62 g of the spent catalyst was charged to a glassfixed-bed reactor, then contacted with a halogen-containing gas streamcontaining nitrogen (1850 mL/min), chlorine gas (2 volume % in nitrogen,50 mL/min), and fluorine gas (1 volume % in nitrogen, 100 mL/min). Thespent catalyst was contacted for 6 hr at 200° C. with thehalogen-containing gas stream. The halogenated spent catalyst was thencontacted with a decoking gas stream containing a mixture of air (100mL/min) and nitrogen (1900 mL/min). The reactor temperature was rampedslowly from 200° C. to 500° C. over 8 hr and then held at 500° C. for 24hr. Molecular hydrogen (1330 mL/min) was then contacted with thede-coked catalyst at 500° C. for 20 hr. This general procedure wasfollowed for Examples 1-47, except for the process changes to thisgeneral procedure noted in the discussion of Examples 1-47 below. TableI summarizes the rejuvenation results for Examples 1-47.

In Examples 1-9, Example 1 was the fresh catalyst baseline. For Example2, the carbon burn step was performed on the spent catalyst at a peaktemperature of 550° C., followed by halogenation with Cl₂/F₂ (volumeratio of 2:1) at 300° C. For Example 3, the sequence of steps wasreversed: the spent catalyst was halogenated with Cl₂/F₂ (volume ratioof 2:1) at 300° C., followed by the carbon burn step at a peaktemperature of 550° C. Unexpectedly, the order of the steps resulted insignificantly different catalyst performance. The spent catalyst whichwas halogenated first (Example 3) had a much lower SOR temperature, ascompared to the spent catalyst which was de-coked first (928° F. versus994° F.), demonstrating the unexpected benefit of performing thehalogenation step prior to the carbon burn step.

For Examples 4-5, halogenation of the spent catalyst with Cl₂/F₂ wasconducted at 300° C. In Example 4, the halogenation gas stream contained1000 ppmv of Cl₂, 500 ppmv F₂, 1 volume % O₂, and the balance N₂, whilethe halogenation gas stream of Example 5 contained 500 ppmv of Cl₂, 500ppmv F₂, 1 volume % O₂, and the balance N₂. Hence, the volume ratio ofCl:F was 2:1 in Example 4 and 1:1 in Example 5. Surprisingly, thereduction in the Cl:F ratio resulted in only minor decreases in catalystperformance: SOR from 914° F. to 916° F., and FR from 28 to 33 m° F./hr.

For Examples 6-9, halogenation with Cl₂/F₂ (volume ratio of 2:1) wasfirst conducted at 300° C., followed by the carbon burn step at a peaktemperature of 550° C., 500° C., 475° C., or 450° C., respectively.Unexpectedly, the results demonstrated that the peak temperature of thecarbon burn can be reduced to 450° C. (Example 9) from 550° C. (Example6) with only a minor loss of catalyst activity: SOR temperatureincreased from 928° F. to 952° F., and fouling rate FR increased from 14to 30 m° F./hr.

In Examples 10-14, Example 10 was the fresh catalyst baseline. ForExamples 11-14, the spent catalyst was halogenated with Cl₂/F₂ (volumeratio of 2:1) at a temperature of 300° C., 200° C., 100° C., or roomtemperature, respectively. The results demonstrated that halogenationtemperatures over 100° C. (e.g., 200-300° C., Examples 11-12) improvedthe catalyst performance. At temperatures of 100° C. and below, inferiorcatalysts with higher SOR temperatures and higher fouling rates wereproduced.

In Examples 15-18, Example 15 was the fresh catalyst baseline. The spentcatalyst of Example 16 was pre-dried in a mixture of air (100 mL/min)and nitrogen (1900 mL/min) at 260° C., the spent catalyst of Example 17was pre-dried in N₂, and the spent catalyst in Example 18 was notpre-dried. Subsequent halogenation with Cl₂/F₂ (volume ratio of 1:1) wasconducted at 260° C. for these examples. Purging of Examples 16-17 wasconducted in a mixture of air and nitrogen at 260° C. De-coking ofExamples 16-18 was conducted at 500° C. Surprisingly, pre-drying in aninert gas prior to halogenation and subsequent carbon burn (Example 17;SOR 914° F.) produced a far superior catalyst compared to that formed bypre-drying in an air/nitrogen mixture (Example 16; SOR 927° F.).

In Examples 19-32, Example 19 was the fresh catalyst baseline. Each ofthe spent catalysts of Examples 20-23 was pre-dried in N₂ at 200° C.Subsequent halogenation with Cl₂/F₂ (volume ratio of 1:1) was conductedat 200° C. in a mixture of air and nitrogen for Example 20, at 200° C.in nitrogen for Example 21, at 260° C. in a mixture of air and nitrogenfor Example 22, and at 260° C. in nitrogen for Example 23. Decoking ofall examples was conducted in a mixture of air and nitrogen at 500° C.Unexpectedly, the composition of the gas stream during halogenationaffected the catalyst performance. Rejuvenated catalyst produced usingan inert gas (e.g., Example 21; SOR 916° F.) during the halogenationstep performed better than the catalyst produced when an air/nitrogenmixture was used (e.g., Example 20; SOR 930° F.).

Each of the spent catalysts of Examples 24-25 was pre-dried in N₂ at200° C., halogenated in a mixture of air and nitrogen with Cl₂/F₂(volume ratio of 1:1) at 200° C., and de-coked at 500° C. Prior to thepre-drying step, the spent catalyst of Example 25 underwent a re-cokingpretreatment at 500° C. with molecular hydrogen and an aromatizationfeed containing C₆-C₈ alkanes and/or cycloalkanes and less than 5 wt. %aromatics, while Example 24 was not pretreated. More specifically, thearomatization feed used contained from 22 to 26 wt. % n-hexane, 4 to 8wt. % n-heptane, 33 to 37 wt. % C₆ iso-paraffins, 17 to 21 wt. % C₇iso-paraffins, 6 to 10 wt. % C₈ iso-paraffins, with the balanceattributable to C₆ and C₇ olefins, naphthenes, and aromatics.Surprisingly, the re-coking pretreatment prior to halogenationsignificantly improved catalyst activity. Rejuvenated catalyst using there-coking pretreatment (Example 25; SOR 917° F.) had improvedperformance over the untreated catalyst (Example 24; SOR 930° F.).

Each of the spent catalysts of Examples 26-29 was halogenated innitrogen with Cl₂/F₂ (volume ratio of 1:1) at 200° C., and de-coked at500° C. A subsequent reduction step was conducted with 10 mole % H₂ innitrogen at 500° C. for Example 26, with 100% H₂ at 500° C. for Example27, with 20 mole % H₂ in nitrogen at 500° C. for Example 28, and with100% H₂ at 500° C. for Example 29 (duplicate of Example 27).Unexpectedly, the amount of molecular hydrogen present in the reducingstep affected the catalyst performance Rejuvenated catalysts producedwith high mole % molecular hydrogen (Examples 27 and 29) during thereducing step performed better than the catalysts produced when low mole% molecular hydrogen was used.

Each of the spent catalysts of Examples 30-32 was halogenated in anitrogen stream containing Cl₂/F₂, de-coked in a mixture of air andnitrogen at 500° C., and reduced in 100% H₂ at 500° C. In Example 30,the halogenation gas stream contained 500 ppmv of Cl₂ and 500 ppmv F₂and the halogenation time was 6 hr; in Example 31, the halogenation gasstream contained 1,100 ppmv of Cl₂ and 1,100 ppmv F₂ and thehalogenation time was 3 hr; and in Example 32, the halogenation gasstream contained 2,200 ppmv of Cl₂ and 2,200 ppmv F₂ and thehalogenation time was 1.5 hr. The results demonstrated that the time forthe halogenation step can be reduced with an increase in the halogenconcentration in the nitrogen stream (e.g., 1,100 ppmv each of Cl₂ andF₂ for 3 hr in Example 31).

In Examples 33-37, Example 33 was the fresh catalyst baseline. Example34 was not subjected to any hydrocarbon treatment, while Example 35 washydrocarbon treated before halogenation, Example 36 was hydrocarbontreated during halogenation, and Example 37 was hydrocarbon treatedafter halogenation but before the carbon burn step. Halogenation wasperformed under inert conditions with Cl₂/F₂ (volume ratio of 1:1), andthe carbon burn was conducted in the mixture of air and nitrogen.Similar to Example 25, the hydrocarbon treatment stream was thearomatization feed (containing from 22 to 26 wt. % n-hexane, 4 to 8 wt.% n-heptane, 33 to 37 wt. % C₆ iso-paraffins, 17 to 21 wt. % C₇iso-paraffins, 6 to 10 wt. % C₈ iso-paraffins, with the balanceattributable to C₆ and C₇ olefins, naphthenes, and aromatics), but withno molecular hydrogen. As with Example 25, the hydrocarbon treatmentprior to halogenation of Example 35 was beneficial. Surprisingly,however, the hydrocarbon treatment after halogenation, but before thecarbon burn step, of Example 37 was even more beneficial in improvingrejuvenated catalyst performance.

In Examples 38-47, Example 38 was the fresh catalyst baseline. ForExamples 39-41, the spent catalyst was halogenated with Cl₂/F₂ (volumeratio of 1:1) in nitrogen at a temperature of 200° C., 260° C., or 370°C., respectively. Unexpectedly, the results demonstrated that the lowerhalogenation temperatures of 200-260° C. provided superior catalystperformed as compared to the higher halogenation temperature of 370° C.

For Examples 42-45, halogenation of the spent catalyst with Cl₂/F₂ wasconducted at 260° C. The volume ratio of Cl:F was 2:1 in Example 42, 1:1in Example 43, 0.67:1 in Example 44, and 0.5:1 in Example 45. Underthese conditions, the rejuvenated catalyst with the best overallcatalyst performance was obtained at a Cl:F ratio of 1:1.

Each of the spent catalysts of Examples 46-47 was halogenated withCl₂/F₂ (volume ratio of 1:1) at 200° C., and de-coked in the mixture ofair and nitrogen at 500° C. The carbon burn time for Example 46 was 16hr, while the carbon burn time for Example 47 was 1 hr. The gas streamafter contacting the spent catalyst was monitored for carbon dioxidelevels to determine when sufficient de-coking had occurred. In theseexamples, 1 hr at 500° C. was sufficient for the carbon burn step.

TABLE I Examples 1-47. SOR TOS. EOR FR Example Catalyst T60 (° F.) (hr)T60 (° F.) (m° F./hr) 1 Fresh 911 140 919 56.4 2 Spent 994 — — — 3 Spent928 140 929 14.0 4 Spent 914 163 918 28.2 5 Spent 916 164 922 33.2 6Spent 928 140 929 14.0 7 Spent 914 163 918 28.2 8 Spent 911 164 917 37.49 Spent 952 163 956 30.3 10 Fresh 906 138 910 28.0 11 Spent 914 163 91828.2 12 Spent 912 163 914 18.4 13 Spent 963 68 966 44.0 14 Spent 991 201000 — 15 Fresh 911 140 919 56.4 16 Spent 927 140 936 67.8 17 Spent 914163 921 43.6 18 Spent 913 116 924 93.7 19 Fresh 902 168 902 1.9 20 Spent930 43 932 44.4 21 Spent 916 120 915 — 22 Spent 913 96 914 13.1 23 Spent910 145 912 14.7 24 Spent 930 43 932 44.4 25 Spent 917 144 919 18.5 26Spent 908 120 912 40.9 27 Spent 906 144 907 17.0 28 Spent 913 144 92055.4 29 Spent 905 144 909 31.2 30 Spent 906 144 907 17.0 31 Spent 905144 908 16.7 32 Spent 909 144 912 19.0 33 Fresh 898 144 906 54.3 34Spent 912 96 917 56.0 35 Spent 909 144 915 44.2 36 Spent 988 24 979 — 37Spent 904 120 904 12.8 38 Fresh 902 144 907 55.5 39 Spent 914 144 91728.9 40 Spent 908 144 914 38.3 41 Spent 928 120 933 50.2 42 Spent 927 72930 46.2 43 Spent 908 144 914 38.3 44 Spent 919 143 922 30.7 45 Spent917 144 925 68.5 46 Spent 917 138 922 45.6 47 Spent 914 144 917 28.9

Examples 48-49

The fresh aromatization catalyst (Example 48) was a Pt/KL-zeolitecontaining approximately 1 wt. % platinum, and 0.828 wt. % Cl and 0.837wt. % F (determined via XRF), with a surface area of approximately 177.5m²/g, a pore volume of 0.19 cc/g, and a micropore volume of 0.0615 cc/g.The source of the spent catalyst was the fresh catalyst, but after ithas been deactivated after long-term use in an aromatization process.Prior to usage in these examples, the spent aromatization catalyst wassubjected to a mild partial decoking treatment at 200° C. to removeunreacted hydrocarbons and light carbonaceous deposits from thecatalyst.

The rejuvenation process was conducted as follows. Approximately 62 g ofthe spent catalyst was charged to a glass fixed-bed reactor, andcontacted with a pre-drying gas stream containing nitrogen (2000 mL/min)at 200° C. for 20 hr. The gas stream was changed to a halogen-containinggas stream containing nitrogen (1750 mL/min), chlorine gas (2 volume %in nitrogen, 50 mL/min), and fluorine gas (1 volume % in nitrogen, 200mL/min), and the spent catalyst was contacted for 3 hr at 200° C. withthe halogen-containing gas stream. The halogenated spent catalyst wasthen contacted with a purging gas stream containing nitrogen (2000mL/min) at 200° C. for 20 hr. Next, a decoking gas stream was charged tothe reactor and contacted with the halogenated spent catalyst. Thedecoking gas stream contained air (100 mL/min) and nitrogen (1900mL/min). The reactor temperature was ramped slowly from 200° C. to 500°C. over 6 hr and then held at 500° C. for 20 hr. The reactor and thede-coked catalyst were cooled down with a mixture of air (100 mL/min)and nitrogen (1900 mL/min). This rejuvenated catalyst is Example 49.

The catalyst performance of the rejuvenated catalyst of Example 49 wascompared to that of the fresh catalyst of Example 48. An aromatizationfeedstock was used for the catalyst comparison. The results indicatedthat the catalyst activity of the rejuvenated catalyst of Example 49 wasslightly lower than the fresh catalyst of Example 48, while theselectivity using the rejuvenated catalyst was equal to or superior tothat of the fresh catalyst.

Examples 50-55

The fresh aromatization catalyst (Example 50) was a Pt/KL-zeolitecontaining approximately 1 wt. % platinum, and 0.828 wt. % Cl and 0.837wt. % F (determined via XRF), with a surface area of approximately 177.5m²/g, a pore volume of 0.19 cc/g, and a micropore volume of 0.0615 cc/g.The source of the spent catalyst was the fresh catalyst, but after ithas been deactivated after long-term use in an aromatization process.This spent catalyst had less carbon/coke deposition than that of thespent catalyst in Examples 48-49. Prior to usage in these examples, thespent aromatization catalyst was subjected to a mild partial decokingtreatment at 200° C. to remove unreacted hydrocarbons and lightcarbonaceous deposits from the catalyst. The spent catalyst (Example 51)contained approximately 1 wt. % platinum, 0.19 wt. % Cl, and 0.05 wt. %F (determined via XRF).

The rejuvenation process was conducted as follows. Approximately 61 g ofthe spent catalyst was charged to a glass fixed-bed reactor, andcontacted with a pre-drying gas stream containing nitrogen (2000 mL/min)at 200° C. for 20 hr. The gas stream was changed to a halogen-containinggas stream containing nitrogen (1750 mL/min), chlorine gas (2 volume %in nitrogen, 50 mL/min), and fluorine gas (1 volume % in nitrogen, 200mL/min), and the spent catalyst was contacted for 3 hr at 200° C. withthe halogen-containing gas stream. The halogenated spent catalyst wasthen contacted with a purging gas stream containing nitrogen (2000mL/min) at 200° C. for 20 hr. Next, a decoking gas stream was charged tothe reactor and contacted with the halogenated spent catalyst. Thedecoking gas stream contained air (100 mL/min) and nitrogen (1900mL/min). The reactor temperature was ramped slowly from 200° C. to apeak decoking temperature in the 400-500° C. range over 6 hr and thenheld at the peak temperature for up to 44 hr (Examples 52-55). Thereactor and the de-coked catalyst were cooled down with a mixture of air(100 mL/min) and nitrogen (1900 mL/min). Table II summarizes variousdecoking conditions and the resultant rejuvenated catalyst properties.

TABLE II Examples 50-55. Peak Decoking Surface Pore Mirco-Pore DecokingTime Wt. Wt. Wt. Area Volume Volume Example Catalyst (° C.) (hr) % Pt %Cl % F (m2/g) (cc/g) (cc/g) 50 Fresh — — 1 0.828 0.837 177  0.191 0.061551 Spent — — 0.999 0.188 0.046 — — — 52 — 500 16 0.991 0.621 0.632 870.131 0.0285 53 — 435 16 0.993 0.644 0.733 99 0.147 0.0260 54 — 400 200.976 0.682 0.808 94 0.149 0.0290 55 — 400 44 0.967 0.640 0.695 98 0.1500.0265

Examples 56-60

In Examples 56-60, the spent aromatization catalyst and general treatingor rejuvenating procedure were the same as provided above for Examples1-47, except for the process changes as follows. For Examples 56-58, thehalogenation gas stream contained 500 ppmv of Cl₂, 1000 ppmv F₂, and thebalance N₂ (volume ratio of Cl:F equal to 1:2), and the halogenationstep was conducted for 3 hr at a temperature of 200° C., 100° C., and25° C. (ambient), respectively. For Example 59, the spent catalyst wasfirst contacted with a chlorination gas stream containing 500 ppmv ofCl₂ (balance N₂) for 3 hr at 200° C., then contacted with a fluorinationgas stream containing 1000 ppmv of F₂ (balance N₂) for 3 hr at 25° C.(ambient). For Example 60, the spent catalyst was first contacted with afluorination gas stream containing 1000 ppmv of F₂ (balance N₂) for 3 hrat 25° C. (ambient), then contacted with a chlorination gas streamcontaining 500 ppmv of Cl₂ (balance N₂) for 3 hr at 200° C.

Table III summarizes the initial Start of Run temperature (SOR) tomaintain the total yield of benzene and toluene at 60 wt. % over time atthe standard test conditions described above, as well as the SORtemperature to maintain the total yield of benzene and toluene at 75 wt.% over time at the same standard test conditions. Unexpectedly, thesequential addition of fluorine followed by chlorine at the respectivetemperatures resulted in a rejuvenated catalyst with superiorperformance (Example 60; SOR(60) equal to 907° F., and SOR(75) equal to948° F.).

TABLE III Examples 56-60. SOR SOR Example Catalyst T60 (° F.) T75 (° F.)56 Spent 921 962 57 Spent 930 — 58 Spent 950 999 59 Spent 947 991 60Spent 907 948

Examples 61-63

For Examples 62-63, Example 61 was the fresh catalyst baseline. InExamples 62-63, the spent aromatization catalyst and general treating orrejuvenating procedure were the same as provided above for Examples1-47, except for the process changes as follows. For Example 62, 60 g ofthe spent catalyst was first contacted with a fluorination gas streamcontaining 500 ppmv of F₂ (balance N₂) for 3 hr at 25° C. (ambient),then contacted with a chlorination gas stream containing 500 ppmv of Cl₂(balance N₂) for 3 hr at 200° C. For Example 63, 60 g of the spentcatalyst was first contacted with a fluorination gas stream containing250 ppmv of F₂ (balance N₂) for 6 hr at 25° C. (ambient), then contactedwith a chlorination gas stream containing 250 ppmv of Cl₂ (balance N₂)for 6 hr at 200° C.

Table IV summarizes the initial Start of Run temperature (SOR) tomaintain the total yield of benzene and toluene at 60 wt. % over time atthe standard test conditions described above, as well as the SORtemperature to maintain the total yield of benzene and toluene at 75 wt.% over time at the same standard test conditions. The respective totaltime on stream (TOS) and yield of C₄ by-products at both 60 wt. % and at75 wt. % also are listed in Table IV. Notably, based on the SORtemperatures, the catalysts of both Example 62 and Example 63 performedsimilar to that of the fresh catalyst of Example 61. The amount of C₄by-products, surprisingly, was reduced by using lower fluorine andchlorine concentrations during the catalyst rejuvenation (Example 63).

TABLE IV Examples 61-63. SOR TOS₆₀ C₄ @ 60 SOR TOS₇₅ C₄ @ 75 ExampleCatalyst T60 (° F.) (hr) (wt. %) T75 (° F.) (hr) (wt. %) 61 Fresh 902 553.1 954 336 4.3 62 Spent 899 55 3.0 953 336 5.2 63 Spent 906 48 2.6 954336 3.9

The invention has been described above with reference to numerousembodiments and specific examples. Many variations will suggestthemselves to those skilled in the art in light of the above detaileddescription. All such obvious variations are within the full intendedscope of the appended claims. Other embodiments of the invention caninclude, but are not limited to, the following:

Embodiment 1

A reforming method comprising:

(A) contacting a hydrocarbon feed with an aromatization catalystcomprising a transition metal and a catalyst support under reformingconditions in a reactor system to produce an aromatic product;

(B) performing step (A) for a time period sufficient to form a spentaromatization catalyst;

(C) contacting the spent aromatization catalyst with afluorine-containing stream comprising a fluorine-containing compound toproduce a fluorinated spent catalyst;

(D) contacting the fluorinated spent catalyst with a chlorine-containingstream comprising a chlorine-containing compound to produce afluorinated-chlorinated spent catalyst; and

(E) contacting the fluorinated-chlorinated spent catalyst with adecoking gas stream comprising oxygen.

Embodiment 2

A reforming method comprising:

(A) contacting a hydrocarbon feed with an aromatization catalystcomprising a transition metal and a catalyst support under reformingconditions in a reactor system to produce an aromatic product;

(B) performing step (A) for a time period sufficient to form a spentaromatization catalyst;

(C) contacting the spent aromatization catalyst with achlorine-containing stream comprising a chlorine-containing compound toproduce a chlorinated spent catalyst;

(D) contacting the chlorinated spent catalyst with a fluorine-containingstream comprising a fluorine-containing compound to produce achlorinated-fluorinated spent catalyst; and

(E) contacting the chlorinated-fluorinated spent catalyst with adecoking gas stream comprising oxygen.

Embodiment 3

The method defined in embodiment 1 or 2, wherein the reforming method isan in situ process, for example, steps (A)-(E) are performed in the samereactor system.

Embodiment 4

The method defined in embodiment 1 or 2, wherein steps (C)-(E) areperformed externally to the reactor system of steps (A)-(B), forexample, steps (C)-(E) are performed in a vessel that is not in thereforming reactor system.

Embodiment 5

The method defined in any of embodiments 1-4, further comprising a stepof reactivating the catalyst after step (E).

Embodiment 6

A method of treating (or regenerating) a spent catalyst comprising atransition metal and a catalyst support, the method comprising:

(1) contacting the spent catalyst with a fluorine-containing streamcomprising a fluorine-containing compound to produce a fluorinated spentcatalyst;

(2) contacting the fluorinated spent catalyst with a chlorine-containingstream comprising a chlorine-containing compound to produce afluorinated-chlorinated spent catalyst; and

(3) contacting the fluorinated-chlorinated spent catalyst with adecoking gas stream comprising oxygen.

Embodiment 7

A method of treating (or regenerating) a spent catalyst comprising atransition metal and a catalyst support, the method comprising:

(1) contacting the spent catalyst with a chlorine-containing streamcomprising a chlorine-containing compound to produce a chlorinated spentcatalyst;

(2) contacting the chlorinated spent catalyst with a fluorine-containingstream comprising a fluorine-containing compound to produce achlorinated-fluorinated spent catalyst; and

(3) contacting the chlorinated-fluorinated spent catalyst with adecoking gas stream comprising oxygen.

Embodiment 8

The method defined in any of embodiments 1-7, wherein thefluorine-containing stream comprises (or consists essentially of, orconsists of) the fluorine-containing compound and any inert gasdisclosed herein, for example, nitrogen.

Embodiment 9

The method defined in any of embodiments 1-8, wherein thefluorine-containing stream comprises (or consists essentially of, orconsists of) fluorine gas (F₂) and nitrogen.

Embodiment 10

The method defined in any of embodiments 1-9, wherein thefluorine-containing stream comprises a concentration of fluorine (F)less than any maximum amount or in any range disclosed herein, forexample, less than about 25,000 ppmv, in a range from about 50 to about2,500 ppmv, or in a range from about 250 to about 2,000 ppmv.

Embodiment 11

The method defined in any of embodiments 1-10, wherein thefluorine-containing stream is substantially free of oxygen-containingcompounds and/or chlorine-containing compounds, for example, less than100 ppmw.

Embodiment 12

The method defined in any of embodiments 1-11, wherein the fluorinationstep is conducted at a fluorination temperature in any fluorinationtemperature range disclosed herein, for example, from about 0° C. toabout 500° C., from about 25° C. to about 250° C., or from about 50° C.to about 280° C.

Embodiment 13

The method defined in any of embodiments 1-12, wherein the fluorinationstep is conducted for a time period in any range of fluorination timeperiods disclosed herein, for example, from about 1 to about 48 hours,from about 1 to about 12 hours, or from about 2 to about 8 hours.

Embodiment 14

The method defined in any of embodiments 1-13, wherein thechlorine-containing stream comprises (or consists essentially of, orconsists of) the chlorine-containing compound and any inert gasdisclosed herein, for example, nitrogen.

Embodiment 15

The method defined in any of embodiments 1-14, wherein thechlorine-containing stream comprises (or consists essentially of, orconsists of) chlorine gas (Cl₂) and nitrogen.

Embodiment 16

The method defined in any of embodiments 1-15, wherein thechlorine-containing stream comprises a concentration of chlorine (Cl)less than any maximum amount or in any range disclosed herein, forexample, less than about 25,000 ppmv, in a range from about 50 to about2,500 ppmv, or in a range from about 250 to about 2,000 ppmv.

Embodiment 17

The method defined in any of embodiments 1-16, wherein thechlorine-containing stream is substantially free of oxygen-containingcompounds and/or fluorine-containing compounds, for example, less than100 ppmw.

Embodiment 18

The method defined in any of embodiments 1-17, wherein the chlorinationstep is conducted at a chlorination temperature in any chlorinationtemperature range disclosed herein, for example, from about 0° C. toabout 500° C., from about 25° C. to about 250° C., or from about 50° C.to about 280° C.

Embodiment 19

The method defined in any of embodiments 1-18, wherein the chlorinationstep is conducted for a time period in any range of chlorination timeperiods disclosed herein, for example, from about 1 to about 48 hours,from about 1 to about 12 hours, or from about 2 to about 8 hours.

Embodiment 20

The method defined in any of the preceding embodiments, wherein themethod further comprises a halogen purge step between step (C) and (D)or between step (1) and (2), the halogen purge step comprisingcontacting the fluorinated spent catalyst or chlorinated spent catalystwith a halogen purge stream comprising (or consisting essentially of, orconsisting of) any inert gas disclosed herein, for example, nitrogen.

Embodiment 21

The method defined in embodiment 20, wherein the halogen purge stream issubstantially free of oxygen-containing compounds, for example, lessthan 100 ppmw.

Embodiment 22

The method defined in any of embodiments 20-21, wherein the halogenpurge stream is substantially free of halogen-containing compounds(substantially halogen-free), for example, less than 100 ppmw.

Embodiment 23

The method defined in any of embodiments 20-22, wherein the halogenpurge step is conducted at a halogen purge temperature in any halogenpurge temperature range disclosed herein, for example, from about 0° C.to about 400° C., or from about 25° C. to about 300° C.

Embodiment 24

The method defined in any of embodiments 20-22, wherein the halogenpurge step is conducted for a time period in any range of halogen purgetime periods disclosed herein, for example, from about 1 to about 48hours.

Embodiment 25

The method defined in any of embodiments 20-24, wherein the halogenpurge step is conducted for a time period sufficient to reduce thefluorine content of the outgoing halogen purge stream, after contactingthe fluorinated spent catalyst, to less than any maximum fluorinecontent described herein, for example, less than about 100 ppmw offluorine-containing compounds.

Embodiment 26

The method defined in any of embodiments 20-24, wherein the halogenpurge step is conducted for a time period sufficient to reduce thechlorine content of the outgoing halogen purge stream, after contactingthe chlorinated spent catalyst, to less than any maximum chlorinecontent described herein, for example, less than about 100 ppmw ofchlorine-containing compounds.

Embodiment 27

A reforming method comprising:

(a) contacting a hydrocarbon feed with an aromatization catalystcomprising a transition metal and a catalyst support under reformingconditions in a reactor system to produce an aromatic product;

(b) performing step (a) for a time period sufficient to form a spentaromatization catalyst;

(c) contacting the spent aromatization catalyst with ahalogen-containing stream comprising chlorine and fluorine to produce ahalogenated spent catalyst; and

(d) contacting the halogenated spent catalyst with a decoking gas streamcomprising oxygen.

Embodiment 28

The method defined in embodiment 27, wherein the reforming method is anin situ process, for example, steps (a)-(d) are performed in the samereactor system.

Embodiment 29

The method defined in embodiment 27, wherein steps (c)-(d) are performedexternally to the reactor system of steps (a)-(b), for example, steps(c)-(d) are performed in a vessel that is not in the reforming reactorsystem.

Embodiment 30

The method defined in any of embodiments 27-29, further comprising astep of reactivating the catalyst after step (d).

Embodiment 31

A method of treating (or regenerating) a spent catalyst comprising atransition metal and a catalyst support, the method comprising:

(i) contacting the spent catalyst with a halogen-containing streamcomprising chlorine and fluorine to produce a halogenated spentcatalyst; and

(ii) contacting the halogenated spent catalyst with a decoking gasstream comprising oxygen.

Embodiment 32

The method defined in any of the preceding embodiments, wherein thecatalyst support comprises a zeolite, an amorphous inorganic oxide, orany combination thereof.

Embodiment 33

The method defined in any of the preceding embodiments, wherein thecatalyst support comprises an L-zeolite, a Y-zeolite, a mordenite, anomega zeolite, and/or a beta zeolite.

Embodiment 34

The method defined in any of the preceding embodiments, wherein thecatalyst support comprises a potassium L-zeolite or a bariumion-exchanged L-zeolite.

Embodiment 35

The method defined in any of the preceding embodiments, wherein thespent catalyst comprises a support matrix comprising alumina, silica, amixed oxide thereof, or a mixture thereof.

Embodiment 36

The method defined in any of the preceding embodiments, wherein thetransition metal comprises a Group VIII transition metal.

Embodiment 37

The method defined in any of the preceding embodiments, wherein thetransition metal comprises platinum.

Embodiment 38

The method defined in any of the preceding embodiments, wherein thespent catalyst comprises any weight percentage range of transition metaldisclosed herein, for example, from about 0.1 wt. % to about 10 wt. %,or from about 0.3 wt. % to about 5 wt. %, transition metal, based on theweight of the spent catalyst excluding carbon.

Embodiment 39

The method defined in any of the preceding embodiments, wherein thespent catalyst comprises any weight percentage range of platinumdisclosed herein, for example, from about 0.1 wt. % to about 10 wt. %,or from about 0.5 wt. % to about 2 wt. %, platinum, based on the weightof the spent catalyst excluding carbon.

Embodiment 40

The method defined in any of the preceding embodiments, wherein thespent catalyst comprises platinum on a KL-zeolite.

Embodiment 41

The method defined in any of the preceding embodiments, wherein thespent catalyst further comprises chlorine and fluorine.

Embodiment 42

The method defined in embodiment 41, wherein the spent catalystcomprises any weight percentage range of chlorine and/or weightpercentage range of fluorine disclosed herein, for example, from about0.025 wt. % to about 5 wt. % fluorine and/or from about 0.025 wt. % toabout 5 wt. % chlorine, based on the weight of the spent catalystexcluding carbon.

Embodiment 43

The method defined in any of embodiments 1-26 or 41-42, wherein thespent catalyst comprises any molar ratio of chlorine:fluorine disclosedherein, for example, from about 0.5:1 to about 4:1.

Embodiment 44

The method defined in any of embodiments 27-43, wherein the molar ratioof Cl:F in the halogen-containing stream is in any range of molar ratiosdisclosed herein, for example, from about 0.2:1 to about 10:1.

Embodiment 45

The method defined in any of embodiments 27-44, wherein thehalogen-containing stream comprises a chlorine-containing compound and afluorine-containing compound.

Embodiment 46

The method defined in any of embodiments 1-26 or 45, wherein thechlorine-containing compound comprises hydrochloric acid, chlorine gas(Cl₂), carbon tetrachloride, tetrachloroethylene, chlorobenzene, methylchloride, methylene chloride, chloroform, allyl chloride,trichloroethylene, a chloramine, a chlorine oxide, a chlorine acid,chlorine dioxide, dichlorine monoxide, dichlorine heptoxide, chloricacid, perchloric acid, ammonium chloride, tetramethylammonium chloride,tetraethylammonium chloride, tetrapropylammonium chloride,tetrabutylammonium chloride, methyltriethylammonium chloride, or anycombination thereof.

Embodiment 47

The method defined in any of embodiments 1-26 or 45-46, wherein thechlorine-containing compound comprises chlorine gas (Cl₂).

Embodiment 48

The method defined in any of embodiments 1-26 or 45-47, wherein thefluorine-containing compound comprises hydrofluoric acid, fluorine gas,2,2,2-trifluoroethanol, tetrafluoroethylene, carbon tetrafluoride,carbon trifluoride, fluoromethane, heptafluoropropane, decafluorobutane,hexafluoroisopropanol, tetrafluoropropanol, pentafluoropropanol,hexafluorophenylpropanol, perfluorobutyl alcohol, hexafluor-2-propanol,pentafluoro-1-propanol, tetrafluoro-1-propanol,1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol,ammonium fluoride, tetramethylammonium fluoride, tetraethylammoniumfluoride, tetrapropylammonium fluoride, tetrabutylammonium fluoride,methyltriethylammonium fluoride or any combination thereof.

Embodiment 49

The method defined in any of embodiments 1-26 or 45-48, wherein thefluorine-containing compound comprises fluorine gas (F₂).

Embodiment 50

The method defined in any of embodiments 27-49, wherein thehalogen-containing stream comprises a chlorine/fluorine-containingcompound or chlorofluorocarbon.

Embodiment 51

The method defined in any of embodiments 27-50, wherein thehalogen-containing stream comprises (or consists essentially of, orconsists of) chlorine, fluorine, and any inert gas disclosed herein, forexample, nitrogen.

Embodiment 52

The method defined in any of embodiments 27-51, wherein thehalogen-containing stream comprises (or consists essentially of, orconsists of) chlorine gas (Cl₂), fluorine gas (F₂), and nitrogen.

Embodiment 53

The method defined in any of embodiments 27-52, wherein thehalogen-containing stream comprises a concentration of chlorine (Cl) anda concentration of fluorine (F) less than any maximum amount or in anyrange disclosed herein, for example, less than about 25,000 ppmv, in arange from about 50 to about 2,500 ppmv, or in a range from about 250 toabout 2,000 ppmv.

Embodiment 54

The method defined in any of embodiments 27-53, wherein thehalogen-containing stream is substantially free of oxygen-containingcompounds, for example, less than 100 ppmw.

Embodiment 55

The method defined in any of embodiments 27-54, wherein the halogenationstep is conducted at a halogenation temperature in any halogenationtemperature range disclosed herein, for example, from about 0° C. toabout 500° C., from about 25° C. to about 250° C., or from about 50° C.to about 280° C.

Embodiment 56

The method defined in any of embodiments 27-55, wherein the halogenationstep is conducted for a time period in any range of halogenation timeperiods disclosed herein, for example, from about 1 to about 48 hours,from about 1 to about 12 hours, or from about 2 to about 8 hours.

Embodiment 57

The method defined in any of the preceding embodiments, wherein thedecoking gas stream comprises (or consists essentially of, or consistsof) any combination of an inert gas (one or more) and oxygen disclosedherein, for example, a mixture of nitrogen and oxygen, air, etc.

Embodiment 58

The method defined in any of the preceding embodiments, wherein thedecoking gas stream comprises a mole % of oxygen less than any maximumamount or in any range disclosed herein, for example, less than about 5mole %, or in a range from about 0.5 to about 3 mole %.

Embodiment 59

The method defined in any of the preceding embodiments, wherein thedecoking gas stream is substantially free of halogen-containingcompounds (substantially halogen-free), for example, less than 100 ppmw.

Embodiment 60

The method defined in any of the preceding embodiments, wherein thedecoking gas stream is substantially free of water, for example, lessthan 100 ppmw.

Embodiment 61

The method defined in any of the preceding embodiments, wherein thecarbon burn step is conducted at a peak decoking temperature in any peakdecoking temperature range disclosed herein, for example, from about300° C. to about 600° C., or from about 350° C. to about 450° C.

Embodiment 62

The method defined in any of the preceding embodiments, wherein thecarbon burn step is started at an initial decoking temperature which isthe same as any halogenation, fluorination, or chlorination temperaturedisclosed herein, for example, in a range from about 0° C. to about 500°C., from about 25° C. to about 250° C., or from about 50° C. to about280° C.

Embodiment 63

The method defined in any of the preceding embodiments, wherein thecarbon burn step is conducted for a time period in any range ofde-coking time periods disclosed herein, for example, from about 1 toabout 48 hours, or from about 1 to about 6 hours.

Embodiment 64

The method defined in any of the preceding embodiments, wherein thecarbon burn step is conducted for a time period sufficient to reduce thewt. % of carbon on the halogenated spent catalyst (orfluorinated-chlorinated spent catalyst, or chlorinated-fluorinated spentcatalyst) to less than any maximum weight percentage of carbon disclosedherein, for example, less than about 1 wt. %.

Embodiment 65

The method defined in any of the preceding embodiments, wherein themethod further comprises a partial decoking step prior to thehalogenation, fluorination, or chlorination step, the partial decokingstep comprising contacting the spent catalyst with a partial decokinggas stream comprising oxygen.

Embodiment 66

The method defined in embodiment 65, wherein the partial decoking gasstream comprises (or consists essentially of, or consists of) anycombination of an inert gas (one or more) and oxygen disclosed herein,for example, a mixture of nitrogen and oxygen, air, etc.

Embodiment 67

The method defined in any of embodiments 65-66, wherein the partialdecoking gas stream comprises a mole % of oxygen less than any maximumamount or in any range disclosed herein, for example, less than about 5mole %, or in a range from about 0.5 to about 3 mole %.

Embodiment 68

The method defined in any of embodiments 65-67, wherein the partialdecoking gas stream is substantially free of halogen-containingcompounds (substantially halogen-free), for example, less than 100 ppmw.

Embodiment 69

The method defined in any of embodiments 65-68, wherein the decoking gasstream is substantially free of water, for example, less than 100 ppmw.

Embodiment 70

The method defined in any of embodiments 65-69, wherein the partialdecoking step is conducted at a partial decoking temperature in anypartial decoking temperature range disclosed herein, for example, fromabout 150° C. to about 250° C.

Embodiment 71

The method defined in any of embodiments 65-70, wherein the partialdecoking step is conducted for a time period in any range of partialde-coking time periods disclosed herein, for example, from about 2 toabout 24 hours.

Embodiment 72

The method defined in any of embodiments 65-71, wherein the partialdecoking step is conducted for a time period sufficient to reduce thewt. % of carbon on the spent catalyst to any range of weight percentageof carbon disclosed herein, for example, from about 1 to 10 wt. %, orfrom about 4 to about 5 wt. %.

Embodiment 73

The method defined in any of the preceding embodiments, wherein themethod further comprises a pre-drying step prior to the halogenation,fluorination, or chlorination step, the pre-drying step comprisingcontacting the spent catalyst with a pre-drying gas stream comprising(or consisting essentially of, or consisting of) any inert gas disclosedherein, for example, nitrogen.

Embodiment 74

The method defined in embodiment 73, wherein the pre-drying gas streamis substantially free of oxygen-containing compounds, for example, lessthan 100 ppmw.

Embodiment 75

The method defined in any of embodiments 73-74, wherein the pre-dryingstep is conducted at a pre-drying temperature in any pre-dryingtemperature range disclosed herein, for example, from about 100° C. toabout 500° C., from about 0° C. to about 400° C., or from about 180° C.to about 280° C.

Embodiment 76

The method defined in any of embodiments 73-75, wherein the pre-dryingstep is conducted for a time period in any range of pre-drying timeperiods disclosed herein, for example, from about 1 to about 48 hours.

Embodiment 77

The method defined in any of embodiments 73-76, wherein the pre-dryingstep is conducted for a time period sufficient to reduce the moisturecontent of the spent catalyst to less than any maximum moisture contentof the spent catalyst disclosed herein, for example, less than about 4wt. %, or less than about 1 wt. %.

Embodiment 78

The method defined in any of the preceding embodiments, wherein themethod further comprises a re-coking pretreatment step prior to thehalogenation, fluorination, or chlorination step, the re-cokingpretreatment step comprising contacting the spent catalyst with apretreatment stream comprising a hydrocarbon feed and molecularhydrogen.

Embodiment 79

The method defined in embodiment 78, wherein the hydrocarbon feedcomprises C₆-C₈ alkanes and/or cycloalkanes.

Embodiment 80

The method defined in any of embodiments 78-79, wherein the pretreatmentstep is conducted at a pretreatment temperature in any pretreatmenttemperature range disclosed herein, for example, from about 100° C. toabout 600° C.

Embodiment 81

The method defined in any of embodiments 78-80, wherein the pretreatmentstep is conducted for a time period in any range of pretreatment timeperiods disclosed herein, for example, from about 1 to about 48 hours.

Embodiment 82

The method defined in any of embodiments 78-81, wherein the pretreatmentstep is conducted for a time period sufficient to add any range ofweight percentage of coke or carbon build-up to the spent catalystdisclosed herein, for example, from about 1 to about 2 wt. %.

Embodiment 83

The method defined in any of the preceding embodiments, wherein themethod further comprises a purging step prior to the carbon burn step,the purging step comprising contacting the halogenated spent catalyst(or fluorinated-chlorinated spent catalyst, or chlorinated-fluorinatedspent catalyst) with a purging stream comprising (or consistingessentially of, or consisting of) any inert gas disclosed herein, forexample, nitrogen.

Embodiment 84

The method defined in embodiment 83, wherein the purging stream issubstantially free of oxygen-containing compounds, for example, lessthan 100 ppmw.

Embodiment 85

The method defined in any of embodiments 83-84, wherein the purgingstream is substantially free of halogen-containing compounds(substantially halogen-free), for example, less than 100 ppmw.

Embodiment 86

The method defined in any of embodiments 83-85, wherein the purging stepis conducted at a purging temperature in any purging temperature rangedisclosed herein, for example, from about 0° C. to about 400° C., fromabout 25° C. to about 300° C., or from about 180° C. to about 280° C.

Embodiment 87

The method defined in any of embodiments 83-86, wherein the purging stepis conducted for a time period in any range of purging time periodsdisclosed herein, for example, from about 1 to about 48 hours.

Embodiment 88

The method defined in any of embodiments 83-87, wherein the purging stepis conducted for a time period sufficient to reduce the halogen contentof the outgoing purging stream, after contacting the halogenated spentcatalyst (or the fluorinated-chlorinated spent catalyst, or thechlorinated-fluorinated spent catalyst), to less than any maximumhalogen content described herein, for example, less than about 100 ppmwof halogen-containing compounds.

Embodiment 89

The method defined in any of the preceding embodiments, wherein themethod further comprises a hydrocarbon treatment step prior to thecarbon burn step, the hydrocarbon treatment step comprising contactingthe halogenated spent catalyst (or fluorinated-chlorinated spentcatalyst, or chlorinated-fluorinated spent catalyst) with a hydrocarbontreatment stream comprising a hydrocarbon feed.

Embodiment 90

The method defined in embodiment 89, wherein the hydrocarbon feedcomprises C₆-C₈ alkanes and/or cycloalkanes.

Embodiment 91

The method defined in any of embodiments 89-90, wherein the hydrocarbontreatment step is conducted at a hydrocarbon treatment temperature inany hydrocarbon treatment temperature range disclosed herein, forexample, from about 400° C. to about 600° C.

Embodiment 92

The method defined in any of embodiments 89-91, wherein the hydrocarbontreatment step is conducted for a time period in any range ofhydrocarbon treatment time periods disclosed herein, for example, fromabout 1 to about 48 hours.

Embodiment 93

The method defined in any of the preceding embodiments, wherein themethod further comprises a reducing step after the carbon burn step, thereducing step comprising contacting the de-coked catalyst with areducing gas stream comprising (or consisting essentially of, orconsisting of) molecular hydrogen.

Embodiment 94

The method defined in embodiment 93, wherein the reducing gas streamcomprises a mole % of molecular hydrogen greater than any minimum amountor in any range disclosed herein, for example, greater than about 25mole %, or greater than about 75 mole %.

Embodiment 95

The method defined in any of embodiments 93-94, wherein the reducingstep is conducted at a peak reducing temperature in any peak reducingtemperature range disclosed herein, for example, from about 400° C. toabout 600° C.

Embodiment 96

The method defined in any of embodiments 93-95, wherein the reducingstep is started at an initial reducing temperature which is the same asany halogenation, fluorination, or chlorination temperature disclosedherein, for example, in a range from about 0° C. to about 500° C., fromabout 25° C. to about 250° C., or from about 50° C. to about 280° C.

Embodiment 97

The method defined in any of embodiments 93-96, wherein the reducingstep is conducted for a time period in any range of reducing step timeperiods disclosed herein, for example, from about 10 to about 30 hours.

Embodiment 98

A reactivated or rejuvenated catalyst produced by the method defined inany of the preceding embodiments.

Embodiment 99

The catalyst defined in embodiment 98, wherein the reactivated orrejuvenated catalyst has an activity from about 50% to about 80% of thecatalyst activity of fresh aromatization catalyst of the same productionrun of catalyst, when tested on the same equipment, and under the samemethod and test conditions.

Embodiment 100

The catalyst defined in any of embodiments 98-99, wherein thereactivated or rejuvenated catalyst has a fouling rate that is equal toor less than that of fresh aromatization catalyst from the sameproduction run of catalyst.

Embodiment 101

The catalyst defined in any of embodiments 98-100, wherein thereactivated or rejuvenated catalyst has an EOR temperature that iswithin +/−8° C. of the EOR temperature of the fresh aromatizationcatalyst from the same production run of catalyst.

That which is claimed is:
 1. A method of treating a spent catalystcomprising a transition metal and a catalyst support, the methodcomprising: (1) contacting the spent catalyst with a fluorine-containingstream comprising a fluorine-containing compound to produce afluorinated spent catalyst; (2) contacting the fluorinated spentcatalyst with a chlorine-containing stream comprising achlorine-containing compound to produce a fluorinated-chlorinated spentcatalyst; and (3) contacting the fluorinated-chlorinated spent catalystwith a decoking gas stream comprising oxygen.
 2. The method of claim 1,wherein: step (1) is conducted at a fluorination temperature in a rangefrom about 25° C. to about 250° C.; and a concentration of fluorine (F)in the fluorine-containing stream is less than about 2,500 ppm byvolume.
 3. The method of claim 2, wherein the fluorine-containing streamis substantially free of oxygen-containing compounds.
 4. The method ofclaim 1, wherein the fluorine-containing stream comprises F₂ andnitrogen.
 5. The method of claim 1, wherein: step (2) is conducted at achlorination temperature in a range from about 150° C. to about 300° C.;and a concentration of chlorine (Cl) in the chlorine-containing streamis less than about 2,500 ppm by volume.
 6. The method of claim 5,wherein the chlorine-containing stream is substantially free ofoxygen-containing compounds.
 7. The method of claim 1, wherein thechlorine-containing stream comprises Cl₂ and nitrogen.
 8. The method ofclaim 1, further comprising a halogen purge step prior to step (2), thehalogen purge step comprising contacting the fluorinated spent catalystwith a halogen purge stream consisting essentially of an inert gas. 9.The method of claim 1, wherein: step (3) is conducted at a peak decokingtemperature in a range from about 300° C. to about 500° C.; the decokinggas stream comprises air or a mixture of nitrogen and oxygen; and thedecoking gas stream is substantially free of halogen-containingcompounds.
 10. The method of claim 1, wherein the spent catalystcomprises: platinum on a KL-zeolite; a support matrix comprisingalumina, silica, a mixed oxide thereof, or a mixture thereof; from about0.025 wt. % to about 5 wt. % chlorine; and from about 0.025 wt. % toabout 5 wt. % fluorine.
 11. The method of claim 1, further comprising: apre-drying step prior to step (1), the pre-drying step comprisingcontacting the spent catalyst with a pre-drying gas stream consistingessentially of an inert gas; a re-coking pretreatment step prior to step(1), the re-coking pretreatment step comprising contacting the spentcatalyst with a pretreatment stream comprising molecular hydrogen and ahydrocarbon feed comprising C₆-C₈ alkanes and/or cycloalkanes; a partialdecoking step prior to step (1), the partial decoking step comprisingcontacting the spent catalyst with a partial decoking gas streamcomprising oxygen at a partial decoking temperature in a range fromabout 150° C. to about 250° C.; or any combination thereof.
 12. Themethod of claim 1, further comprising a reducing step after step (3),the reducing step comprising contacting the de-coked catalyst with areducing gas stream comprising molecular hydrogen.
 13. The method ofclaim 1, further comprising: a purging step prior to step (3), thepurging step comprising contacting the fluorinated-chlorinated spentcatalyst with a purging stream consisting essentially of an inert gas; ahydrocarbon treatment step prior to step (3), the hydrocarbon treatmentstep comprising contacting the fluorinated-chlorinated spent catalystwith a hydrocarbon treatment stream comprising a hydrocarbon feedcomprising C₆-C₈ alkanes and/or cycloalkanes; or both.
 14. A rejuvenatedcatalyst produced by the method of claim
 1. 15. A method of treating aspent catalyst comprising a transition metal and a catalyst support, themethod comprising: (1) contacting the spent catalyst with achlorine-containing stream comprising a chlorine-containing compound toproduce a chlorinated spent catalyst; (2) contacting the chlorinatedspent catalyst with a fluorine-containing stream comprising afluorine-containing compound to produce a chlorinated-fluorinated spentcatalyst; and (3) contacting the chlorinated-fluorinated spent catalystwith a decoking gas stream comprising oxygen.
 16. The method of claim15, wherein: step (1) is conducted at a chlorination temperature in arange from about 150° C. to about 300° C.; a concentration of chlorine(Cl) in the chlorine-containing stream is less than about 2,500 ppm byvolume; the chlorine-containing stream comprises Cl₂ and nitrogen, andis substantially free of oxygen-containing compounds; step (2) isconducted at a fluorination temperature in a range from about 25° C. toabout 250° C.; a concentration of fluorine (F) in thefluorine-containing stream is less than about 2,500 ppm by volume; andthe fluorine-containing stream comprises F₂ and nitrogen, and issubstantially free of oxygen-containing compounds.
 17. The method ofclaim 15, wherein the spent catalyst comprises: platinum on aKL-zeolite; a support matrix comprising alumina, silica, a mixed oxidethereof, or a mixture thereof; from about 0.025 wt. % to about 5 wt. %chlorine; and from about 0.025 wt. % to about 5 wt. % fluorine.
 18. Areforming process comprising: (A) contacting a hydrocarbon feed with anaromatization catalyst comprising a transition metal and a catalystsupport under reforming conditions in a reactor system to produce anaromatic product; (B) performing step (A) for a time period sufficientto form a spent aromatization catalyst; (C) contacting the spentaromatization catalyst with a fluorine-containing stream comprising afluorine-containing compound to produce a fluorinated spent catalyst;(D) contacting the fluorinated spent catalyst with a chlorine-containingstream comprising a chlorine-containing compound to produce afluorinated-chlorinated spent catalyst; and (E) contacting thefluorinated-chlorinated spent catalyst with a decoking gas streamcomprising oxygen.
 19. The process of claim 18, wherein the reformingprocess is an in situ process.
 20. The process of claim 18, whereinsteps (C)-(E) are performed in a vessel external to the reactor system.21. A reforming process comprising: (A) contacting a hydrocarbon feedwith an aromatization catalyst comprising a transition metal and acatalyst support under reforming conditions in a reactor system toproduce an aromatic product; (B) performing step (A) for a time periodsufficient to form a spent aromatization catalyst; (C) contacting thespent aromatization catalyst with a chlorine-containing streamcomprising a chlorine-containing compound to produce a chlorinated spentcatalyst; (D) contacting the chlorinated spent catalyst with afluorine-containing stream comprising a fluorine-containing compound toproduce a chlorinated-fluorinated spent catalyst; and (E) contacting thechlorinated-fluorinated spent catalyst with a decoking gas streamcomprising oxygen.
 22. The process of claim 21, wherein the reformingprocess is an in situ process.
 23. The process of claim 21, whereinsteps (C)-(E) are performed in a vessel external to the reactor system.